diff --git a/backend-node/src/app.ts b/backend-node/src/app.ts
index 536b8f46..32ab7332 100644
--- a/backend-node/src/app.ts
+++ b/backend-node/src/app.ts
@@ -134,6 +134,8 @@ import { BatchSchedulerService } from "./services/batchSchedulerService";
 
 const app = express();
 
+app.set("trust proxy", true);
+
 // 기본 미들웨어
 app.use(
   helmet({
diff --git a/backend-node/src/controllers/adminController.ts b/backend-node/src/controllers/adminController.ts
index e1190f6c..6cc62cc6 100644
--- a/backend-node/src/controllers/adminController.ts
+++ b/backend-node/src/controllers/adminController.ts
@@ -10,7 +10,7 @@ import { EncryptUtil } from "../utils/encryptUtil";
 import { FileSystemManager } from "../utils/fileSystemManager";
 import { validateBusinessNumber } from "../utils/businessNumberValidator";
 import { MenuCopyService } from "../services/menuCopyService";
-import { auditLogService } from "../services/auditLogService";
+import { auditLogService, getClientIp } from "../services/auditLogService";
 
 /**
  * 관리자 메뉴 목록 조회
@@ -1199,7 +1199,7 @@ export async function saveMenu(
       resourceName: savedMenu.menu_name_kor,
       summary: `메뉴 "${savedMenu.menu_name_kor}" 생성`,
       changes: { after: { menuNameKor: savedMenu.menu_name_kor, menuUrl: savedMenu.menu_url, status: savedMenu.status } },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -1403,7 +1403,7 @@ export async function updateMenu(
         before: { menuNameKor: currentMenu.menu_name_kor, menuUrl: currentMenu.menu_url, status: currentMenu.status },
         after: { menuNameKor: updatedMenu.menu_name_kor, menuUrl: updatedMenu.menu_url, status: updatedMenu.status },
       },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -1596,7 +1596,7 @@ export async function deleteMenu(
       resourceName: currentMenu.menu_name_kor,
       summary: `메뉴 "${currentMenu.menu_name_kor}" 삭제 (하위 ${childMenuIds.length}개 포함, 총 ${allMenuIdsToDelete.length}건)`,
       changes: { before: { menuNameKor: currentMenu.menu_name_kor } },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -1772,7 +1772,7 @@ export async function deleteMenusBatch(
         resourceType: "MENU",
         summary: `메뉴 일괄 삭제: ${deletedCount}개 삭제, ${failedCount}개 실패`,
         changes: { before: { deletedMenus, failedMenuIds } },
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req),
         requestPath: req.originalUrl,
       });
     }
@@ -1883,7 +1883,7 @@ export async function toggleMenuStatus(
       resourceName: currentMenu.menu_name_kor,
       summary: `메뉴 "${currentMenu.menu_name_kor}" 상태 변경: ${currentStatus} → ${newStatus}`,
       changes: { before: { status: currentStatus }, after: { status: newStatus }, fields: ["status"] },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -2526,7 +2526,7 @@ export const changeUserStatus = async (
         resourceName: currentUser.user_name,
         summary: `사용자 "${currentUser.user_name}" 상태 변경: ${currentUser.status} → ${status}`,
         changes: { before: { status: currentUser.status }, after: { status }, fields: ["status"] },
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req),
         requestPath: req.originalUrl,
       });
 
@@ -2677,7 +2677,7 @@ export const saveUser = async (req: AuthenticatedRequest, res: Response) => {
       resourceName: userData.userName,
       summary: isExistingUser ? `사용자 "${userData.userName}" 정보 수정` : `사용자 "${userData.userName}" 등록`,
       changes: { after: { userId: userData.userId, userName: userData.userName, deptName: userData.deptName, status: userData.status } },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -2881,7 +2881,7 @@ export const createCompany = async (
         resourceName: createdCompany.company_name,
         summary: `회사 "${createdCompany.company_name}" (${createdCompany.company_code}) 등록`,
         changes: { after: { company_code: createdCompany.company_code, company_name: createdCompany.company_name } },
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req),
         requestPath: req.originalUrl,
       });
 
@@ -3127,7 +3127,7 @@ export const updateCompany = async (
         before: { company_name: beforeCompany?.company_name, status: beforeCompany?.status },
         after: { company_name: updatedCompany.company_name, status: updatedCompany.status },
       },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -3202,7 +3202,7 @@ export const deleteCompany = async (
       resourceName: deletedCompany.company_name,
       summary: `회사 "${deletedCompany.company_name}" (${deletedCompany.company_code}) 삭제`,
       changes: { before: { company_code: deletedCompany.company_code, company_name: deletedCompany.company_name } },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -3382,7 +3382,7 @@ export const updateProfile = async (
       resourceName: updatedUser?.user_name || "",
       summary: `프로필 수정 (${updateFields.length}개 항목)`,
       changes: { after: { userName, email, tel, cellPhone, locale } },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -3509,7 +3509,7 @@ export const resetUserPassword = async (
         resourceName: currentUser.user_name,
         summary: `사용자 "${currentUser.user_name}" 비밀번호 초기화`,
         changes: { fields: ["user_password"] },
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req),
         requestPath: req.originalUrl,
       });
 
@@ -3723,7 +3723,7 @@ export async function copyMenu(
       resourceId: menuObjid,
       summary: `메뉴(${menuObjid}) → 회사 "${targetCompanyCode}"로 복사`,
       changes: { after: { targetCompanyCode, menuObjid } },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -4051,7 +4051,7 @@ export const saveUserWithDept = async (
       resourceName: userInfo.user_name,
       summary: `사용자 "${userInfo.user_name}" ${isExistingUser ? "수정" : "등록"} (부서: ${mainDept?.dept_name || "없음"})`,
       changes: { after: { userName: userInfo.user_name, email: userInfo.email, deptName: mainDept?.dept_name, status: userInfo.status } },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
diff --git a/backend-node/src/controllers/commonCodeController.ts b/backend-node/src/controllers/commonCodeController.ts
index 4b361434..4b57b846 100644
--- a/backend-node/src/controllers/commonCodeController.ts
+++ b/backend-node/src/controllers/commonCodeController.ts
@@ -6,7 +6,7 @@ import {
 } from "../services/commonCodeService";
 import { AuthenticatedRequest } from "../types/auth";
 import { logger } from "../utils/logger";
-import { auditLogService } from "../services/auditLogService";
+import { auditLogService, getClientIp } from "../services/auditLogService";
 
 export class CommonCodeController {
   private commonCodeService: CommonCodeService;
@@ -172,7 +172,7 @@ export class CommonCodeController {
         resourceId: category?.categoryCode,
         resourceName: category?.categoryName || categoryData.categoryName,
         summary: `코드 카테고리 "${category?.categoryName || categoryData.categoryName}" 생성`,
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req),
         requestPath: req.originalUrl,
       });
 
@@ -229,7 +229,7 @@ export class CommonCodeController {
         resourceId: categoryCode,
         resourceName: category?.categoryName,
         summary: `코드 카테고리 "${categoryCode}" 수정`,
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req),
         requestPath: req.originalUrl,
       });
 
@@ -277,7 +277,7 @@ export class CommonCodeController {
         resourceType: "CODE_CATEGORY",
         resourceId: categoryCode,
         summary: `코드 카테고리 "${categoryCode}" 삭제`,
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req),
         requestPath: req.originalUrl,
       });
 
@@ -347,7 +347,7 @@ export class CommonCodeController {
         resourceId: codeData.codeValue,
         resourceName: codeData.codeName,
         summary: `코드 "${codeData.codeName}" (${categoryCode}) 생성`,
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req),
         requestPath: req.originalUrl,
       });
 
diff --git a/backend-node/src/controllers/ddlController.ts b/backend-node/src/controllers/ddlController.ts
index 07f0b391..631b6360 100644
--- a/backend-node/src/controllers/ddlController.ts
+++ b/backend-node/src/controllers/ddlController.ts
@@ -9,7 +9,7 @@ import { DDLExecutionService } from "../services/ddlExecutionService";
 import { DDLAuditLogger } from "../services/ddlAuditLogger";
 import { CreateTableRequest, AddColumnRequest } from "../types/ddl";
 import { logger } from "../utils/logger";
-import { auditLogService } from "../services/auditLogService";
+import { auditLogService, getClientIp } from "../services/auditLogService";
 
 export class DDLController {
   /**
@@ -70,7 +70,7 @@ export class DDLController {
           tableName,
           summary: `테이블 "${tableName}" 생성 (${columns.length}개 컬럼)`,
           changes: { after: { tableName, columnCount: columns.length, description } },
-          ipAddress: (req as any).ip,
+          ipAddress: getClientIp(req),
           requestPath: req.originalUrl,
         });
 
diff --git a/backend-node/src/controllers/departmentController.ts b/backend-node/src/controllers/departmentController.ts
index 43e56f7e..8238284f 100644
--- a/backend-node/src/controllers/departmentController.ts
+++ b/backend-node/src/controllers/departmentController.ts
@@ -3,7 +3,7 @@ import { logger } from "../utils/logger";
 import { AuthenticatedRequest } from "../types/auth";
 import { ApiResponse } from "../types/common";
 import { query, queryOne } from "../database/db";
-import { auditLogService } from "../services/auditLogService";
+import { auditLogService, getClientIp } from "../services/auditLogService";
 
 /**
  * 부서 목록 조회 (회사별)
@@ -182,7 +182,7 @@ export async function createDepartment(req: AuthenticatedRequest, res: Response)
       tableName: "dept_info",
       summary: `부서 "${dept_name.trim()}" 생성`,
       changes: { after: { deptCode, deptName: dept_name.trim(), parentDeptCode: parent_dept_code } },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -246,7 +246,7 @@ export async function updateDepartment(req: AuthenticatedRequest, res: Response)
       tableName: "dept_info",
       summary: `부서 "${dept_name.trim()}" 수정`,
       changes: { after: { deptName: dept_name.trim(), parentDeptCode: parent_dept_code } },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -327,7 +327,7 @@ export async function deleteDepartment(req: AuthenticatedRequest, res: Response)
       tableName: "dept_info",
       summary: `부서 "${result[0].dept_name}" 삭제${memberCount > 0 ? ` (부서원 ${memberCount}명 제외)` : ""}`,
       changes: { before: { deptCode, deptName: result[0].dept_name } },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
diff --git a/backend-node/src/controllers/flowController.ts b/backend-node/src/controllers/flowController.ts
index 180f17fd..62074dbf 100644
--- a/backend-node/src/controllers/flowController.ts
+++ b/backend-node/src/controllers/flowController.ts
@@ -10,7 +10,7 @@ import { FlowConnectionService } from "../services/flowConnectionService";
 import { FlowExecutionService } from "../services/flowExecutionService";
 import { FlowDataMoveService } from "../services/flowDataMoveService";
 import { FlowProcedureService } from "../services/flowProcedureService";
-import { auditLogService } from "../services/auditLogService";
+import { auditLogService, getClientIp } from "../services/auditLogService";
 
 export class FlowController {
   private flowDefinitionService: FlowDefinitionService;
@@ -102,7 +102,7 @@ export class FlowController {
         resourceName: flowDef?.name || name,
         summary: `플로우 "${flowDef?.name || name}" 생성`,
         changes: { after: { name, tableName } },
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req as any),
         requestPath: req.originalUrl,
       });
 
@@ -229,7 +229,7 @@ export class FlowController {
           before: { name: beforeFlow?.name, description: beforeFlow?.description, isActive: beforeFlow?.isActive },
           after: { name, description, isActive },
         },
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req as any),
         requestPath: req.originalUrl,
       });
 
@@ -272,7 +272,7 @@ export class FlowController {
         resourceType: "FLOW",
         resourceId: String(flowId),
         summary: `플로우(ID:${flowId}) 삭제`,
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req as any),
         requestPath: req.originalUrl,
       });
 
@@ -372,7 +372,7 @@ export class FlowController {
         resourceName: stepName,
         summary: `플로우 스텝 "${stepName}" 생성 (플로우 ID:${flowDefinitionId})`,
         changes: { after: { stepName, tableName, stepOrder } },
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req as any),
         requestPath: req.originalUrl,
       });
 
@@ -467,7 +467,7 @@ export class FlowController {
           before: { stepName: beforeStep?.stepName, tableName: beforeStep?.tableName, stepOrder: beforeStep?.stepOrder },
           after: { stepName, tableName, stepOrder },
         },
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req as any),
         requestPath: req.originalUrl,
       });
 
@@ -524,7 +524,7 @@ export class FlowController {
         resourceId: String(id),
         resourceName: existingStep?.stepName,
         summary: `플로우 스텝 "${existingStep?.stepName || id}" 삭제`,
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req as any),
         requestPath: req.originalUrl,
       });
 
@@ -623,7 +623,7 @@ export class FlowController {
         resourceName: flowDef?.name || "",
         summary: `플로우 "${flowDef?.name}" 연결 생성 (${fromStep?.stepName} → ${toStep?.stepName})`,
         changes: { after: { fromStepId, toStepId, label } },
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req as any),
         requestPath: req.originalUrl,
       });
 
@@ -680,7 +680,7 @@ export class FlowController {
         resourceId: String(existingConn?.flowDefinitionId || id),
         summary: `플로우 연결 삭제 (ID: ${id})`,
         changes: { before: { connectionId: id } },
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req as any),
         requestPath: req.originalUrl,
       });
 
diff --git a/backend-node/src/controllers/numberingRuleController.ts b/backend-node/src/controllers/numberingRuleController.ts
index fe71a617..68f12dde 100644
--- a/backend-node/src/controllers/numberingRuleController.ts
+++ b/backend-node/src/controllers/numberingRuleController.ts
@@ -9,7 +9,7 @@ import {
 } from "../middleware/authMiddleware";
 import { numberingRuleService } from "../services/numberingRuleService";
 import { logger } from "../utils/logger";
-import { auditLogService } from "../services/auditLogService";
+import { auditLogService, getClientIp } from "../services/auditLogService";
 
 const router = Router();
 
@@ -199,7 +199,7 @@ router.post(
         resourceName: ruleConfig.ruleName,
         summary: `채번 규칙 "${ruleConfig.ruleName}" 생성`,
         changes: { after: { ruleName: ruleConfig.ruleName, prefix: ruleConfig.prefix } },
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req),
         requestPath: req.originalUrl,
       });
 
@@ -251,7 +251,7 @@ router.put(
           before: { ruleName: beforeRule?.ruleName, prefix: beforeRule?.prefix },
           after: updates,
         },
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req),
         requestPath: req.originalUrl,
       });
 
@@ -289,7 +289,7 @@ router.delete(
         resourceType: "NUMBERING_RULE",
         resourceId: ruleId,
         summary: `채번 규칙(ID:${ruleId}) 삭제`,
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req),
         requestPath: req.originalUrl,
       });
 
diff --git a/backend-node/src/controllers/roleController.ts b/backend-node/src/controllers/roleController.ts
index c70149e2..06f72f31 100644
--- a/backend-node/src/controllers/roleController.ts
+++ b/backend-node/src/controllers/roleController.ts
@@ -8,7 +8,7 @@ import {
   isCompanyAdmin,
   canAccessCompanyData,
 } from "../utils/permissionUtils";
-import { auditLogService } from "../services/auditLogService";
+import { auditLogService, getClientIp } from "../services/auditLogService";
 
 /**
  * 권한 그룹 목록 조회
@@ -190,7 +190,7 @@ export const createRoleGroup = async (
       resourceName: authName,
       summary: `권한 그룹 "${authName}" 생성`,
       changes: { after: { authName, authCode, companyCode } },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -271,7 +271,7 @@ export const updateRoleGroup = async (
         before: { authName: existingRoleGroup.authName, authCode: existingRoleGroup.authCode, status: existingRoleGroup.status },
         after: { authName, authCode, status },
       },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -343,7 +343,7 @@ export const deleteRoleGroup = async (
       resourceId: String(objid),
       resourceName: existingRoleGroup.authName,
       summary: `권한 그룹 "${existingRoleGroup.authName}" 삭제`,
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
diff --git a/backend-node/src/controllers/screenManagementController.ts b/backend-node/src/controllers/screenManagementController.ts
index 68f580f0..1827640c 100644
--- a/backend-node/src/controllers/screenManagementController.ts
+++ b/backend-node/src/controllers/screenManagementController.ts
@@ -1,7 +1,7 @@
 import { Response } from "express";
 import { screenManagementService } from "../services/screenManagementService";
 import { AuthenticatedRequest } from "../types/auth";
-import { auditLogService } from "../services/auditLogService";
+import { auditLogService, getClientIp } from "../services/auditLogService";
 
 // 화면 목록 조회
 export const getScreens = async (req: AuthenticatedRequest, res: Response) => {
@@ -120,7 +120,7 @@ export const createScreen = async (
       resourceName: newScreen?.screenName || screenData.screenName,
       summary: `화면 "${newScreen?.screenName || screenData.screenName}" 생성`,
       changes: { after: { screenName: newScreen?.screenName, tableName: newScreen?.tableName } },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -162,7 +162,7 @@ export const updateScreen = async (
         before: { screenName: beforeScreen?.screenName, tableName: beforeScreen?.tableName, isActive: beforeScreen?.isActive },
         after: { screenName: updateData.screenName, tableName: updateData.tableName, isActive: updateData.isActive },
       },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -264,7 +264,7 @@ export const updateScreenInfo = async (
         before: { screenName: beforeScreen?.screenName, tableName: beforeScreen?.tableName, description: beforeScreen?.description, isActive: beforeScreen?.isActive },
         after: { screenName, tableName, description, isActive },
       },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -330,7 +330,7 @@ export const deleteScreen = async (
       resourceName: screenName,
       summary: `화면(ID:${id}, ${screenName}) 삭제 (사유: ${deleteReason || "없음"})`,
       changes: { before: { deleteReason, force } },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -623,7 +623,7 @@ export const copyScreenWithModals = async (
       resourceName: mainScreen?.screenName,
       summary: `화면 일괄 복사 (메인 1개 + 모달 ${result.modalScreens.length}개, 원본 ID:${id})`,
       changes: { after: { sourceScreenId: id, targetCompanyCode, mainScreenName: mainScreen?.screenName } },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -672,7 +672,7 @@ export const copyScreen = async (
       resourceName: screenName,
       summary: `화면 "${screenName}" 복사 (원본 ID:${id})`,
       changes: { after: { sourceScreenId: id, screenName, screenCode } },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -786,7 +786,7 @@ export const saveLayout = async (req: AuthenticatedRequest, res: Response) => {
       resourceId: screenId,
       resourceName: screenInfo?.screenName || "",
       summary: `화면(ID:${screenId}, ${screenInfo?.screenName || ""}) 레이아웃 저장`,
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -877,7 +877,7 @@ export const saveLayoutV2 = async (req: AuthenticatedRequest, res: Response) =>
       resourceId: screenId,
       resourceName: screenInfo?.screenName || "",
       summary: `화면(ID:${screenId}, ${screenInfo?.screenName || ""}) V2 레이아웃 저장`,
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -1064,7 +1064,7 @@ export const saveLayoutPop = async (req: AuthenticatedRequest, res: Response) =>
       resourceId: screenId,
       resourceName: screenInfo?.screenName || "",
       summary: `화면(ID:${screenId}, ${screenInfo?.screenName || ""}) POP 레이아웃 저장`,
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
diff --git a/backend-node/src/controllers/tableManagementController.ts b/backend-node/src/controllers/tableManagementController.ts
index 68f5b33b..b8436176 100644
--- a/backend-node/src/controllers/tableManagementController.ts
+++ b/backend-node/src/controllers/tableManagementController.ts
@@ -13,7 +13,7 @@ import {
   ColumnSettingsResponse,
 } from "../types/tableManagement";
 import { query } from "../database/db";
-import { auditLogService } from "../services/auditLogService";
+import { auditLogService, getClientIp } from "../services/auditLogService";
 
 /**
  * 테이블 목록 조회
@@ -974,7 +974,7 @@ export async function addTableData(
       tableName,
       summary: `${tableName} 데이터 추가`,
       changes: { after: data },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -1127,7 +1127,7 @@ export async function editTableData(
         tableName,
         summary: `${tableName} 데이터 수정`,
         changes: { before: changedBefore, after: changedAfter },
-        ipAddress: (req as any).ip,
+        ipAddress: getClientIp(req),
         requestPath: req.originalUrl,
       });
     }
@@ -1461,7 +1461,7 @@ export async function deleteTableData(
       tableName,
       summary: `${tableName} 데이터 삭제 (${deletedCount}건)`,
       changes: { before: { deletedCount, items: deleteItems.length } },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
@@ -2355,7 +2355,7 @@ export async function multiTableSave(
       tableName: mainTableName,
       summary: `${mainTableName} 데이터 ${isUpdate ? "수정" : "생성"}${subTableResults.length > 0 ? ` (서브 테이블 ${subTableResults.length}건)` : ""}`,
       changes: { after: mainData },
-      ipAddress: (req as any).ip,
+      ipAddress: getClientIp(req),
       requestPath: req.originalUrl,
     });
 
diff --git a/backend-node/src/services/auditLogService.ts b/backend-node/src/services/auditLogService.ts
index 67c3b72d..bc77be49 100644
--- a/backend-node/src/services/auditLogService.ts
+++ b/backend-node/src/services/auditLogService.ts
@@ -1,6 +1,20 @@
+import { Request } from "express";
 import { query, pool } from "../database/db";
 import logger from "../utils/logger";
 
+export function getClientIp(req: Request): string {
+  const forwarded = req.headers["x-forwarded-for"];
+  if (forwarded) {
+    const first = Array.isArray(forwarded) ? forwarded[0] : forwarded.split(",")[0];
+    return first.trim();
+  }
+  const realIp = req.headers["x-real-ip"];
+  if (realIp) {
+    return Array.isArray(realIp) ? realIp[0] : realIp;
+  }
+  return req.ip || req.socket?.remoteAddress || "unknown";
+}
+
 export type AuditAction =
   | "CREATE"
   | "UPDATE"
diff --git a/backend-node/src/services/numberingRuleService.ts b/backend-node/src/services/numberingRuleService.ts
index 2888a1f3..6f6fe81c 100644
--- a/backend-node/src/services/numberingRuleService.ts
+++ b/backend-node/src/services/numberingRuleService.ts
@@ -68,6 +68,155 @@ interface NumberingRuleConfig {
 }
 
 class NumberingRuleService {
+  /**
+   * 순번(sequence) 파트를 제외한 나머지 파트 값들을 조합해 prefix_key 생성
+   * 이 키가 같으면 같은 순번 계열, 다르면 001부터 재시작
+   */
+  private async buildPrefixKey(
+    rule: NumberingRuleConfig,
+    formData?: Record<string, any>
+  ): Promise<string> {
+    const sortedParts = [...rule.parts].sort((a: any, b: any) => a.order - b.order);
+    const prefixParts: string[] = [];
+
+    for (const part of sortedParts) {
+      if (part.partType === "sequence") continue;
+
+      if (part.generationMethod === "manual") {
+        // 수동 입력 파트는 prefix에서 제외 (값이 매번 달라질 수 있으므로)
+        continue;
+      }
+
+      const autoConfig = (part as any).autoConfig || {};
+
+      switch (part.partType) {
+        case "date": {
+          const dateFormat = autoConfig.dateFormat || "YYYYMMDD";
+          if (autoConfig.useColumnValue && autoConfig.sourceColumnName && formData) {
+            const columnValue = formData[autoConfig.sourceColumnName];
+            if (columnValue) {
+              const dateValue = columnValue instanceof Date ? columnValue : new Date(columnValue);
+              if (!isNaN(dateValue.getTime())) {
+                prefixParts.push(this.formatDate(dateValue, dateFormat));
+                break;
+              }
+            }
+          }
+          prefixParts.push(this.formatDate(new Date(), dateFormat));
+          break;
+        }
+
+        case "text": {
+          prefixParts.push(autoConfig.textValue || "TEXT");
+          break;
+        }
+
+        case "number": {
+          const length = autoConfig.numberLength || 3;
+          const value = autoConfig.numberValue || 1;
+          prefixParts.push(String(value).padStart(length, "0"));
+          break;
+        }
+
+        case "category": {
+          const categoryKey = autoConfig.categoryKey;
+          const categoryMappings = autoConfig.categoryMappings || [];
+
+          if (!categoryKey || !formData) {
+            prefixParts.push("");
+            break;
+          }
+
+          const columnName = categoryKey.includes(".")
+            ? categoryKey.split(".")[1]
+            : categoryKey;
+          const selectedValue = formData[columnName];
+
+          if (!selectedValue) {
+            prefixParts.push("");
+            break;
+          }
+
+          const selectedValueStr = String(selectedValue);
+          let mapping = categoryMappings.find((m: any) => {
+            if (m.categoryValueId?.toString() === selectedValueStr) return true;
+            if (m.categoryValueCode && m.categoryValueCode === selectedValueStr) return true;
+            if (m.categoryValueLabel === selectedValueStr) return true;
+            return false;
+          });
+
+          if (!mapping) {
+            try {
+              const pool = getPool();
+              const [catTableName, catColumnName] = categoryKey.includes(".")
+                ? categoryKey.split(".")
+                : [categoryKey, categoryKey];
+              const cvResult = await pool.query(
+                `SELECT value_id, value_label FROM category_values 
+                 WHERE table_name = $1 AND column_name = $2 AND value_code = $3 LIMIT 1`,
+                [catTableName, catColumnName, selectedValueStr]
+              );
+              if (cvResult.rows.length > 0) {
+                const resolvedId = cvResult.rows[0].value_id;
+                const resolvedLabel = cvResult.rows[0].value_label;
+                mapping = categoryMappings.find((m: any) => {
+                  if (m.categoryValueId?.toString() === String(resolvedId)) return true;
+                  if (m.categoryValueLabel === resolvedLabel) return true;
+                  return false;
+                });
+              }
+            } catch { /* ignore */ }
+          }
+
+          prefixParts.push(mapping?.format || selectedValueStr);
+          break;
+        }
+
+        default:
+          break;
+      }
+    }
+
+    return prefixParts.join("|");
+  }
+
+  /**
+   * prefix_key 기반으로 현재 순번 조회 (새 테이블 사용)
+   */
+  private async getSequenceForPrefix(
+    client: any,
+    ruleId: string,
+    companyCode: string,
+    prefixKey: string
+  ): Promise<number> {
+    const result = await client.query(
+      `SELECT current_sequence FROM numbering_rule_sequences 
+       WHERE rule_id = $1 AND company_code = $2 AND prefix_key = $3`,
+      [ruleId, companyCode, prefixKey]
+    );
+    return result.rows.length > 0 ? result.rows[0].current_sequence : 0;
+  }
+
+  /**
+   * prefix_key 기반으로 순번 증가 (UPSERT)
+   */
+  private async incrementSequenceForPrefix(
+    client: any,
+    ruleId: string,
+    companyCode: string,
+    prefixKey: string
+  ): Promise<number> {
+    const result = await client.query(
+      `INSERT INTO numbering_rule_sequences (rule_id, company_code, prefix_key, current_sequence, last_allocated_at)
+       VALUES ($1, $2, $3, 1, NOW())
+       ON CONFLICT (rule_id, company_code, prefix_key)
+       DO UPDATE SET current_sequence = numbering_rule_sequences.current_sequence + 1,
+                     last_allocated_at = NOW()
+       RETURNING current_sequence`,
+      [ruleId, companyCode, prefixKey]
+    );
+    return result.rows[0].current_sequence;
+  }
   /**
    * 규칙 목록 조회 (전체)
    */
@@ -928,12 +1077,19 @@ class NumberingRuleService {
     const rule = await this.getRuleById(ruleId, companyCode);
     if (!rule) throw new Error("규칙을 찾을 수 없습니다");
 
+    // prefix_key 기반 순번 조회
+    const prefixKey = await this.buildPrefixKey(rule, formData);
+    const pool = getPool();
+    const currentSeq = await this.getSequenceForPrefix(pool, ruleId, companyCode, prefixKey);
+
+    logger.info("미리보기: prefix_key 기반 순번 조회", {
+      ruleId, prefixKey, currentSeq,
+    });
+
     const parts = await Promise.all(rule.parts
       .sort((a: any, b: any) => a.order - b.order)
       .map(async (part: any) => {
         if (part.generationMethod === "manual") {
-          // 수동 입력 - 항상 ____ 마커 사용 (프론트엔드에서 편집 가능하게 처리)
-          // placeholder 텍스트는 프론트엔드에서 별도로 표시
           return "____";
         }
 
@@ -941,9 +1097,8 @@ class NumberingRuleService {
 
         switch (part.partType) {
           case "sequence": {
-            // 순번 (다음 할당될 순번으로 미리보기, 실제 증가는 allocate 시)
             const length = autoConfig.sequenceLength || 3;
-            const nextSequence = (rule.currentSequence || 0) + 1;
+            const nextSequence = currentSeq + 1;
             return String(nextSequence).padStart(length, "0");
           }
 
@@ -1129,6 +1284,27 @@ class NumberingRuleService {
       const rule = await this.getRuleById(ruleId, companyCode);
       if (!rule) throw new Error("규칙을 찾을 수 없습니다");
 
+      // prefix_key 기반 순번: 순번 이외 파트 조합으로 prefix 생성
+      const prefixKey = await this.buildPrefixKey(rule, formData);
+      const hasSequence = rule.parts.some((p: any) => p.partType === "sequence");
+
+      // 순번이 있으면 prefix_key 기반으로 UPSERT하여 다음 순번 획득
+      let allocatedSequence = 0;
+      if (hasSequence) {
+        allocatedSequence = await this.incrementSequenceForPrefix(
+          client, ruleId, companyCode, prefixKey
+        );
+        // 호환성을 위해 기존 current_sequence도 업데이트
+        await client.query(
+          "UPDATE numbering_rules SET current_sequence = current_sequence + 1 WHERE rule_id = $1 AND company_code = $2",
+          [ruleId, companyCode]
+        );
+      }
+
+      logger.info("allocateCode: prefix_key 기반 순번 할당", {
+        ruleId, prefixKey, allocatedSequence,
+      });
+
       // 수동 입력 파트가 있고, 사용자가 입력한 코드가 있으면 수동 입력 부분 추출
       const manualParts = rule.parts.filter(
         (p: any) => p.generationMethod === "manual"
@@ -1136,8 +1312,6 @@ class NumberingRuleService {
       let extractedManualValues: string[] = [];
 
       if (manualParts.length > 0 && userInputCode) {
-        // 프리뷰 코드를 생성해서 ____ 위치 파악
-        // 🔧 category 파트도 처리하여 올바른 템플릿 생성
         const previewParts = await Promise.all(rule.parts
           .sort((a: any, b: any) => a.order - b.order)
           .map(async (part: any) => {
@@ -1148,19 +1322,18 @@ class NumberingRuleService {
             switch (part.partType) {
               case "sequence": {
                 const length = autoConfig.sequenceLength || 3;
-                return "X".repeat(length); // 순번 자리 표시
+                return "X".repeat(length);
               }
               case "text":
                 return autoConfig.textValue || "";
               case "date":
-                return "DATEPART"; // 날짜 자리 표시
+                return "DATEPART";
               case "category": {
-                // 카테고리 파트: formData에서 실제 값을 가져와서 매핑된 형식 사용
                 const catKey2 = autoConfig.categoryKey;
                 const catMappings2 = autoConfig.categoryMappings || [];
 
                 if (!catKey2 || !formData) {
-                  return "CATEGORY"; // 폴백
+                  return "CATEGORY";
                 }
 
                 const colName2 = catKey2.includes(".")
@@ -1169,7 +1342,7 @@ class NumberingRuleService {
                 const selVal2 = formData[colName2];
 
                 if (!selVal2) {
-                  return "CATEGORY"; // 폴백
+                  return "CATEGORY";
                 }
 
                 const selValStr2 = String(selVal2);
@@ -1180,7 +1353,6 @@ class NumberingRuleService {
                   return false;
                 });
 
-                // valueCode → valueId 역변환 시도
                 if (!catMapping2) {
                   try {
                     const pool2 = getPool();
@@ -1211,8 +1383,6 @@ class NumberingRuleService {
         const sortedPartsForTemplate = rule.parts.sort((a: any, b: any) => a.order - b.order);
         const previewTemplate = joinPartsWithSeparators(previewParts, sortedPartsForTemplate, rule.separator || "");
 
-        // 사용자 입력 코드에서 수동 입력 부분 추출
-        // 예: 템플릿 "R-____-XXX", 사용자입력 "R-MYVALUE-012" → "MYVALUE" 추출
         const templateParts = previewTemplate.split("____");
         if (templateParts.length > 1) {
           let remainingCode = userInputCode;
@@ -1220,14 +1390,11 @@ class NumberingRuleService {
             const prefix = templateParts[i];
             const suffix = templateParts[i + 1];
 
-            // prefix 이후 부분 추출
             if (prefix && remainingCode.startsWith(prefix)) {
               remainingCode = remainingCode.slice(prefix.length);
             }
 
-            // suffix 이전까지가 수동 입력 값
             if (suffix) {
-              // suffix에서 순번(XXX)이나 날짜 부분을 제외한 실제 구분자 찾기
               const suffixStart = suffix.replace(/X+|DATEPART/g, "");
               const manualEndIndex = suffixStart
                 ? remainingCode.indexOf(suffixStart)
@@ -1254,7 +1421,6 @@ class NumberingRuleService {
         .sort((a: any, b: any) => a.order - b.order)
         .map(async (part: any) => {
           if (part.generationMethod === "manual") {
-            // 추출된 수동 입력 값 사용, 없으면 기본값 사용
             const manualValue =
               extractedManualValues[manualPartIndex] ||
               part.manualConfig?.value ||
@@ -1267,24 +1433,19 @@ class NumberingRuleService {
 
           switch (part.partType) {
             case "sequence": {
-              // 순번 (자동 증가 숫자 - 다음 번호 사용)
               const length = autoConfig.sequenceLength || 3;
-              const nextSequence = (rule.currentSequence || 0) + 1;
-              return String(nextSequence).padStart(length, "0");
+              return String(allocatedSequence).padStart(length, "0");
             }
 
             case "number": {
-              // 숫자 (고정 자릿수)
               const length = autoConfig.numberLength || 3;
               const value = autoConfig.numberValue || 1;
               return String(value).padStart(length, "0");
             }
 
             case "date": {
-              // 날짜 (다양한 날짜 형식)
               const dateFormat = autoConfig.dateFormat || "YYYYMMDD";
 
-              // 컬럼 기준 생성인 경우 폼 데이터에서 날짜 추출
               if (
                 autoConfig.useColumnValue &&
                 autoConfig.sourceColumnName &&
@@ -1292,80 +1453,42 @@ class NumberingRuleService {
               ) {
                 const columnValue = formData[autoConfig.sourceColumnName];
                 if (columnValue) {
-                  // 날짜 문자열 또는 Date 객체를 Date로 변환
                   const dateValue =
                     columnValue instanceof Date
                       ? columnValue
                       : new Date(columnValue);
 
                   if (!isNaN(dateValue.getTime())) {
-                    logger.info("컬럼 기준 날짜 생성", {
-                      sourceColumn: autoConfig.sourceColumnName,
-                      columnValue,
-                      parsedDate: dateValue.toISOString(),
-                    });
                     return this.formatDate(dateValue, dateFormat);
-                  } else {
-                    logger.warn("날짜 변환 실패, 현재 날짜 사용", {
-                      sourceColumn: autoConfig.sourceColumnName,
-                      columnValue,
-                    });
                   }
-                } else {
-                  logger.warn("소스 컬럼 값이 없음, 현재 날짜 사용", {
-                    sourceColumn: autoConfig.sourceColumnName,
-                    formDataKeys: Object.keys(formData),
-                  });
                 }
               }
 
-              // 기본: 현재 날짜 사용
               return this.formatDate(new Date(), dateFormat);
             }
 
             case "text": {
-              // 텍스트 (고정 문자열)
               return autoConfig.textValue || "TEXT";
             }
 
             case "category": {
-              // 카테고리 기반 코드 생성 (allocateCode용)
-              const categoryKey = autoConfig.categoryKey; // 예: "item_info.material"
+              const categoryKey = autoConfig.categoryKey;
               const categoryMappings = autoConfig.categoryMappings || [];
 
               if (!categoryKey || !formData) {
-                logger.warn("allocateCode: 카테고리 키 또는 폼 데이터 없음", {
-                  categoryKey,
-                  hasFormData: !!formData,
-                });
                 return "";
               }
 
-              // categoryKey에서 컬럼명 추출 (예: "item_info.material" -> "material")
               const columnName = categoryKey.includes(".")
                 ? categoryKey.split(".")[1]
                 : categoryKey;
 
-              // 폼 데이터에서 해당 컬럼의 값 가져오기
               const selectedValue = formData[columnName];
 
-              logger.info("allocateCode: 카테고리 파트 처리", {
-                categoryKey,
-                columnName,
-                selectedValue,
-                formDataKeys: Object.keys(formData),
-                mappingsCount: categoryMappings.length,
-              });
-
               if (!selectedValue) {
-                logger.warn("allocateCode: 카테고리 값이 선택되지 않음", {
-                  columnName,
-                  formDataKeys: Object.keys(formData),
-                });
                 return "";
               }
 
-              // 카테고리 매핑에서 해당 값에 대한 형식 찾기
               const selectedValueStr = String(selectedValue);
               let allocMapping = categoryMappings.find((m: any) => {
                 if (m.categoryValueId?.toString() === selectedValueStr) return true;
@@ -1374,7 +1497,6 @@ class NumberingRuleService {
                 return false;
               });
 
-              // valueCode → valueId 역변환 시도
               if (!allocMapping) {
                 try {
                   const pool3 = getPool();
@@ -1391,37 +1513,18 @@ class NumberingRuleService {
                       if (m.categoryValueLabel === rlabel3) return true;
                       return false;
                     });
-                    if (allocMapping) {
-                      logger.info("allocateCode: 카테고리 매핑 역변환 성공", {
-                        valueCode: selectedValueStr, resolvedId: rid3, format: allocMapping.format,
-                      });
-                    }
                   }
                 } catch { /* ignore */ }
               }
 
               if (allocMapping) {
-                logger.info("allocateCode: 카테고리 매핑 적용", {
-                  selectedValue,
-                  format: allocMapping.format,
-                  categoryValueLabel: allocMapping.categoryValueLabel,
-                });
                 return allocMapping.format || "";
               }
 
-              logger.warn("allocateCode: 카테고리 매핑을 찾을 수 없음", {
-                selectedValue,
-                availableMappings: categoryMappings.map((m: any) => ({
-                  id: m.categoryValueId,
-                  code: m.categoryValueCode,
-                  label: m.categoryValueLabel,
-                })),
-              });
               return "";
             }
 
             default:
-              logger.warn("알 수 없는 파트 타입", { partType: part.partType });
               return "";
           }
         }));
@@ -1429,17 +1532,6 @@ class NumberingRuleService {
       const sortedPartsForAlloc = rule.parts.sort((a: any, b: any) => a.order - b.order);
       const allocatedCode = joinPartsWithSeparators(parts, sortedPartsForAlloc, rule.separator || "");
 
-      // 순번이 있는 경우에만 증가
-      const hasSequence = rule.parts.some(
-        (p: any) => p.partType === "sequence"
-      );
-      if (hasSequence) {
-        await client.query(
-          "UPDATE numbering_rules SET current_sequence = current_sequence + 1 WHERE rule_id = $1 AND company_code = $2",
-          [ruleId, companyCode]
-        );
-      }
-
       await client.query("COMMIT");
       logger.info("코드 할당 완료", { ruleId, allocatedCode, companyCode });
       return allocatedCode;
@@ -1492,11 +1584,17 @@ class NumberingRuleService {
 
   async resetSequence(ruleId: string, companyCode: string): Promise<void> {
     const pool = getPool();
+    // 새 테이블의 모든 prefix 순번 초기화
     await pool.query(
-      "UPDATE numbering_rules SET current_sequence = 1, updated_at = NOW() WHERE rule_id = $1 AND company_code = $2",
+      "DELETE FROM numbering_rule_sequences WHERE rule_id = $1 AND company_code = $2",
       [ruleId, companyCode]
     );
-    logger.info("시퀀스 초기화 완료", { ruleId, companyCode });
+    // 기존 테이블도 초기화 (호환성)
+    await pool.query(
+      "UPDATE numbering_rules SET current_sequence = 0, updated_at = NOW() WHERE rule_id = $1 AND company_code = $2",
+      [ruleId, companyCode]
+    );
+    logger.info("시퀀스 초기화 완료 (prefix별 순번 포함)", { ruleId, companyCode });
   }
 
   /**