diff --git a/src/claim-request-management/expert-initiated-claim.mirror.controller.ts b/src/claim-request-management/expert-initiated-claim.mirror.controller.ts
index 21e244d..9045b22 100644
--- a/src/claim-request-management/expert-initiated-claim.mirror.controller.ts
+++ b/src/claim-request-management/expert-initiated-claim.mirror.controller.ts
@@ -4,9 +4,12 @@ import {
   Body,
   Controller,
   Get,
+  HttpException,
+  InternalServerErrorException,
   Param,
   Patch,
   Post,
+  Put,
   Query,
   UploadedFile,
   UseGuards,
@@ -516,6 +519,73 @@ Returns status of each item (uploaded/captured or not).
     );
   }
 
+  // ─── Owner signature on expert pricing ───────────────────────────────────────
+
+  @Put("claim-sign/:claimRequestId")
+  @ApiParam({ name: "claimRequestId" })
+  @ApiConsumes("multipart/form-data")
+  @ApiBody({
+    description: "Signature file, agreement, and branch",
+    schema: {
+      type: "object",
+      required: ["sign", "agree", "branchId"],
+      properties: {
+        sign: { type: "string", format: "binary", description: "Signature image" },
+        agree: { type: "boolean", description: "true to accept, false to reject" },
+        branchId: { type: "string", description: "Insurer branch ID" },
+      },
+    },
+  })
+  @ApiOperation({
+    summary: "Owner signature on expert pricing (Flow 3 — expert acts on behalf of user)",
+    description:
+      "Field expert submits the damaged party's signature during the final approval stage. " +
+      "Delegates to the same service method as the user sign endpoint; the expert's " +
+      "identity is resolved to the claim owner via `resolveClaimEffectiveUserId`.",
+  })
+  @UseInterceptors(
+    FileInterceptor("sign", {
+      limits: { fileSize: DEFAULT_MEDIA_MAX_BYTES },
+      storage: diskStorage({
+        destination: "./files/claim-sign",
+        filename: (req, file, callback) => {
+          const unique = Date.now();
+          const ex = extname(file.originalname);
+          const base = file.originalname.split(/[.,\s-]/)[0] || "sign";
+          callback(null, `${base}-${unique}${ex}`);
+        },
+      }),
+    }),
+  )
+  async submitOwnerSign(
+    @Param("claimRequestId") claimRequestId: string,
+    @Body("agree") agree: string | boolean,
+    @Body("branchId") branchId: string,
+    @CurrentUser() expert: any,
+    @UploadedFile() sign: Express.Multer.File,
+  ) {
+    await this.mediaPolicyService.assertForClaim(sign, claimRequestId, "image");
+    const agreed =
+      typeof agree === "string"
+        ? agree === "true" || agree === "1"
+        : Boolean(agree);
+    try {
+      return await this.claimRequestManagementService.submitOwnerInsurerApprovalSignV2(
+        claimRequestId,
+        agreed,
+        typeof branchId === "string" ? branchId : "",
+        sign,
+        expert.sub,
+        expert,
+      );
+    } catch (error) {
+      if (error instanceof HttpException) throw error;
+      throw new InternalServerErrorException(
+        error instanceof Error ? error.message : "Failed to submit signature",
+      );
+    }
+  }
+
   @Patch("car-capture/:claimRequestId")
   @ApiConsumes("multipart/form-data")
   @UseInterceptors(
diff --git a/src/request-management/file-reviewer-blame-v4.controller.ts b/src/request-management/file-reviewer-blame-v4.controller.ts
index 9eefc09..a95a7be 100644
--- a/src/request-management/file-reviewer-blame-v4.controller.ts
+++ b/src/request-management/file-reviewer-blame-v4.controller.ts
@@ -1,11 +1,15 @@
 import { extname } from "node:path";
 import {
+  BadRequestException,
   Body,
   Controller,
   Get,
+  HttpException,
+  InternalServerErrorException,
   Param,
   Patch,
   Post,
+  Put,
   UploadedFile,
   UseGuards,
   UseInterceptors,
@@ -316,6 +320,73 @@ export class FileReviewerBlameV4Controller {
     );
   }
 
+  // ─── Owner signature on expert pricing ───────────────────────────────────────
+
+  @Put("claim-sign/:claimRequestId")
+  @ApiParam({ name: "claimRequestId" })
+  @ApiConsumes("multipart/form-data")
+  @ApiBody({
+    description: "Signature file, agreement, and branch",
+    schema: {
+      type: "object",
+      required: ["sign", "agree", "branchId"],
+      properties: {
+        sign: { type: "string", format: "binary", description: "Signature image" },
+        agree: { type: "boolean", description: "true to accept, false to reject" },
+        branchId: { type: "string", description: "Insurer branch ID" },
+      },
+    },
+  })
+  @ApiOperation({
+    summary: "Owner signature on expert pricing (V4 — FileReviewer acts on behalf of user)",
+    description:
+      "FileReviewer submits the damaged party's signature during the final approval stage. " +
+      "Delegates to the same service method as the user sign endpoint; the FileReviewer's " +
+      "identity is resolved to the claim owner via `resolveClaimEffectiveUserId`.",
+  })
+  @UseInterceptors(
+    FileInterceptor("sign", {
+      limits: { fileSize: DEFAULT_MEDIA_MAX_BYTES },
+      storage: diskStorage({
+        destination: "./files/claim-sign",
+        filename: (req, file, callback) => {
+          const unique = Date.now();
+          const ex = extname(file.originalname);
+          const base = file.originalname.split(/[.,\s-]/)[0] || "sign";
+          callback(null, `${base}-${unique}${ex}`);
+        },
+      }),
+    }),
+  )
+  async submitOwnerSign(
+    @Param("claimRequestId") claimRequestId: string,
+    @Body("agree") agree: string | boolean,
+    @Body("branchId") branchId: string,
+    @CurrentUser() fileReviewer: any,
+    @UploadedFile() sign: Express.Multer.File,
+  ) {
+    await this.mediaPolicyService.assertForClaim(sign, claimRequestId, "image");
+    const agreed =
+      typeof agree === "string"
+        ? agree === "true" || agree === "1"
+        : Boolean(agree);
+    try {
+      return await this.claimRequestManagementService.submitOwnerInsurerApprovalSignV2(
+        claimRequestId,
+        agreed,
+        typeof branchId === "string" ? branchId : "",
+        sign,
+        fileReviewer.sub,
+        fileReviewer,
+      );
+    } catch (error) {
+      if (error instanceof HttpException) throw error;
+      throw new InternalServerErrorException(
+        error instanceof Error ? error.message : "Failed to submit signature",
+      );
+    }
+  }
+
   // ─── Walk-around video ────────────────────────────────────────────────────────
 
   @Patch("car-capture/:claimRequestId")
diff --git a/src/request-management/file-reviewer-blame-v5.controller.ts b/src/request-management/file-reviewer-blame-v5.controller.ts
index 8fc401a..2c4f522 100644
--- a/src/request-management/file-reviewer-blame-v5.controller.ts
+++ b/src/request-management/file-reviewer-blame-v5.controller.ts
@@ -3,9 +3,12 @@ import {
   Body,
   Controller,
   Get,
+  HttpException,
+  InternalServerErrorException,
   Param,
   Patch,
   Post,
+  Put,
   UploadedFile,
   UseGuards,
   UseInterceptors,
@@ -315,6 +318,73 @@ export class FileReviewerBlameV5Controller {
     );
   }
 
+  // ─── Owner signature on expert pricing ───────────────────────────────────────
+
+  @Put("claim-sign/:claimRequestId")
+  @ApiParam({ name: "claimRequestId" })
+  @ApiConsumes("multipart/form-data")
+  @ApiBody({
+    description: "Signature file, agreement, and branch",
+    schema: {
+      type: "object",
+      required: ["sign", "agree", "branchId"],
+      properties: {
+        sign: { type: "string", format: "binary", description: "Signature image" },
+        agree: { type: "boolean", description: "true to accept, false to reject" },
+        branchId: { type: "string", description: "Insurer branch ID" },
+      },
+    },
+  })
+  @ApiOperation({
+    summary: "Owner signature on expert pricing (V5 — FileReviewer acts on behalf of user)",
+    description:
+      "FileReviewer submits the damaged party's signature during the final approval stage. " +
+      "Delegates to the same service method as the user sign endpoint; the FileReviewer's " +
+      "identity is resolved to the claim owner via `resolveClaimEffectiveUserId`.",
+  })
+  @UseInterceptors(
+    FileInterceptor("sign", {
+      limits: { fileSize: DEFAULT_MEDIA_MAX_BYTES },
+      storage: diskStorage({
+        destination: "./files/claim-sign",
+        filename: (req, file, callback) => {
+          const unique = Date.now();
+          const ex = extname(file.originalname);
+          const base = file.originalname.split(/[.,\s-]/)[0] || "sign";
+          callback(null, `${base}-${unique}${ex}`);
+        },
+      }),
+    }),
+  )
+  async submitOwnerSign(
+    @Param("claimRequestId") claimRequestId: string,
+    @Body("agree") agree: string | boolean,
+    @Body("branchId") branchId: string,
+    @CurrentUser() fileReviewer: any,
+    @UploadedFile() sign: Express.Multer.File,
+  ) {
+    await this.mediaPolicyService.assertForClaim(sign, claimRequestId, "image");
+    const agreed =
+      typeof agree === "string"
+        ? agree === "true" || agree === "1"
+        : Boolean(agree);
+    try {
+      return await this.claimRequestManagementService.submitOwnerInsurerApprovalSignV2(
+        claimRequestId,
+        agreed,
+        typeof branchId === "string" ? branchId : "",
+        sign,
+        fileReviewer.sub,
+        fileReviewer,
+      );
+    } catch (error) {
+      if (error instanceof HttpException) throw error;
+      throw new InternalServerErrorException(
+        error instanceof Error ? error.message : "Failed to submit signature",
+      );
+    }
+  }
+
   // ─── Walk-around video ────────────────────────────────────────────────────────
 
   @Patch("car-capture/:claimRequestId")