diff --git a/src/expert-claim/dto/expert-claim-v2.dto.spec.ts b/src/expert-claim/dto/expert-claim-v2.dto.spec.ts
index 7f45966..4b15b14 100644
--- a/src/expert-claim/dto/expert-claim-v2.dto.spec.ts
+++ b/src/expert-claim/dto/expert-claim-v2.dto.spec.ts
@@ -51,9 +51,9 @@ describe("SubmitExpertReplyV2Dto", () => {
         {
           partId: 201,
           typeOfDamage: TypeOfDamage.Repair,
-          price: "10000",
-          salary: "0",
-          totalPayment: "10000",
+          price: "100000",
+          salary: "100000",
+          totalPayment: "200000",
           factorNeeded: false,
         },
       ],
@@ -69,14 +69,14 @@ describe("SubmitExpertReplyV2Dto", () => {
         {
           partId: 11,
           typeOfDamage: TypeOfDamage.Repair,
-          salary: "۵,۰۰۰",
-          totalPayment: "5000",
+          salary: "۱۰۰,۰۰۰",
+          totalPayment: "100000",
           factorNeeded: false,
         },
         {
           partId: 23,
           typeOfDamage: TypeOfDamage.Change,
-          price: "۵۰,۰۰۰",
+          price: "۱۰۰,۰۰۰",
           salary: "۱۰۰,۰۰۰",
           totalPayment: "150000",
           factorNeeded: false,
diff --git a/src/expert-claim/dto/expert-claim-v2.dto.ts b/src/expert-claim/dto/expert-claim-v2.dto.ts
index 9e49507..144add0 100644
--- a/src/expert-claim/dto/expert-claim-v2.dto.ts
+++ b/src/expert-claim/dto/expert-claim-v2.dto.ts
@@ -27,7 +27,7 @@ export class DaghiDetailsV2Dto {
   option: DaghiOption;
 
   @ApiPropertyOptional({
-    description: `Required when option is '${DaghiOption.RECYCLED_PARTS_VALUE}' (Toman)`,
+    description: `Required when option is '${DaghiOption.RECYCLED_PARTS_VALUE}' (Toman; 100,000 to 10,000,000,000).`,
   })
   @ValidateIf(
     (daghi: DaghiDetailsV2Dto) =>
@@ -63,7 +63,8 @@ export class PartPricingV2Dto {
 
   @ApiPropertyOptional({
     example: "5000000",
-    description: "Required for change lines; omitted for repair lines. Use 0 if unused.",
+    description:
+      "Required for change lines; omitted for repair lines. Every supplied amount must be between 100,000 and 10,000,000,000 Toman.",
   })
   @ValidateIf(
     (part: PartPricingV2Dto) =>
@@ -78,7 +79,8 @@ export class PartPricingV2Dto {
 
   @ApiProperty({
     example: "2000000",
-    description: "Labor in Toman (integer string). Use 0 if the full amount is in price.",
+    description:
+      "Labor in Toman (integer string; 100,000 to 10,000,000,000).",
   })
   @IsString()
   @IsNotEmpty()
@@ -87,7 +89,8 @@ export class PartPricingV2Dto {
 
   @ApiProperty({
     example: "7000000",
-    description: "Line total in Toman (integer string).",
+    description:
+      "Line total in Toman (integer string; 100,000 to 10,000,000,000).",
   })
   @IsString()
   @IsNotEmpty()
@@ -116,10 +119,13 @@ export class PartPricingV2Dto {
 }
 
 export class SubmitExpertReplyV2Dto {
-  @ApiProperty({ example: 'Front door and hood have severe paint damage' })
+  @ApiPropertyOptional({
+    example: 'Front door and hood have severe paint damage',
+    description: "Optional expert note about the damage assessment.",
+  })
+  @IsOptional()
   @IsString()
-  @IsNotEmpty()
-  description: string;
+  description?: string;
 
   @ApiProperty({
     type: [PartPricingV2Dto],
diff --git a/src/expert-claim/expert-claim.service.spec.ts b/src/expert-claim/expert-claim.service.spec.ts
index e9cc395..4884fdc 100644
--- a/src/expert-claim/expert-claim.service.spec.ts
+++ b/src/expert-claim/expert-claim.service.spec.ts
@@ -95,4 +95,45 @@ describe("ExpertClaimService expert-reply pricing", () => {
 
     expect(findByIdAndUpdate).not.toHaveBeenCalled();
   });
+
+  it("returns a Persian, field-specific error when a V2 price is below the minimum", async () => {
+    const service = createService() as any;
+    const findByIdAndUpdate = jest.fn();
+    service.claimCaseDbService = {
+      findById: jest.fn().mockResolvedValue({
+        status: ClaimCaseStatus.EXPERT_REVIEWING,
+        workflow: { locked: true, lockedBy: { actorId: "expert-1" } },
+      }),
+      findByIdAndUpdate,
+    };
+    service.assertExpertActorOnClaim = jest.fn().mockResolvedValue(undefined);
+
+    await expect(
+      service.submitExpertReplyV2(
+        "v2-claim",
+        {
+          description: "Damage assessment",
+          parts: [
+            {
+              partId: 201,
+              typeOfDamage: TypeOfDamage.Repair,
+              price: "99,999",
+              salary: "100000",
+              totalPayment: "100000",
+              factorNeeded: false,
+            },
+          ],
+        },
+        { sub: "expert-1", role: RoleEnum.FIELD_EXPERT },
+      ),
+    ).rejects.toMatchObject({
+      response: {
+        code: "EXPERT_REPLY_VALIDATION_ERROR",
+        field: "parts[0].price",
+        message: expect.stringContaining("حداقل"),
+      },
+    });
+
+    expect(findByIdAndUpdate).not.toHaveBeenCalled();
+  });
 });
diff --git a/src/expert-claim/expert-claim.service.ts b/src/expert-claim/expert-claim.service.ts
index fed0825..125a182 100644
--- a/src/expert-claim/expert-claim.service.ts
+++ b/src/expert-claim/expert-claim.service.ts
@@ -913,6 +913,19 @@ export class ExpertClaimService {
     );
   }
 
+  private expertReplySubmissionError(
+    message: string,
+    code: string,
+    details: Record<string, unknown> = {},
+  ) {
+    return {
+      message,
+      error: "EXPERT_REPLY_SUBMISSION_ERROR",
+      code,
+      ...details,
+    };
+  }
+
   /** Factor validation: expert must send a line amount (OCR is not used for factor photos). */
   private expertFactorValidationDecisionHasLinePricing(decision: {
     totalPayment?: string;
@@ -948,28 +961,53 @@ export class ExpertClaimService {
   private validateAndNormalizeDaghiForExpertReplyV2(
     parts: import("./dto/expert-claim-v2.dto").PartPricingV2Dto[],
   ) {
-    for (const part of parts) {
+    for (const [partIndex, part] of parts.entries()) {
       if (part.typeOfDamage === TypeOfDamage.Repair) continue;
       if (!part.daghi || !part.daghi.option) {
         throw new BadRequestException(
-          `Daghi option is required for part ${part.partId}`,
+          this.expertReplySubmissionError(
+            `گزینه داغی برای قطعه ${part.partId} الزامی است.`,
+            "DAGHI_OPTION_REQUIRED",
+            { field: `parts[${partIndex}].daghi.option`, partId: part.partId },
+          ),
         );
       }
       if (part.daghi.option === DaghiOption.RECYCLED_PARTS_VALUE) {
         if (!part.daghi.price) {
           throw new BadRequestException(
-            `Price is required for part ${part.partId} when option is '${DaghiOption.RECYCLED_PARTS_VALUE}'`,
+            this.expertReplySubmissionError(
+              `قیمت داغی برای قطعه ${part.partId} الزامی است.`,
+              "DAGHI_PRICE_REQUIRED",
+              {
+                field: `parts[${partIndex}].daghi.price`,
+                partId: part.partId,
+              },
+            ),
           );
         }
       } else if (part.daghi.option === DaghiOption.DELIVER_DAMAGED_PART) {
         if (!part.daghi.branchId) {
           throw new BadRequestException(
-            `Branch ID is required for part ${part.partId} when option is '${DaghiOption.DELIVER_DAMAGED_PART}'`,
+            this.expertReplySubmissionError(
+              `شعبه تحویل داغی برای قطعه ${part.partId} الزامی است.`,
+              "DAGHI_BRANCH_REQUIRED",
+              {
+                field: `parts[${partIndex}].daghi.branchId`,
+                partId: part.partId,
+              },
+            ),
           );
         }
         if (!Types.ObjectId.isValid(part.daghi.branchId)) {
           throw new BadRequestException(
-            `Invalid branch ID format for part ${part.partId}`,
+            this.expertReplySubmissionError(
+              `شناسه شعبه برای قطعه ${part.partId} معتبر نیست.`,
+              "DAGHI_BRANCH_INVALID",
+              {
+                field: `parts[${partIndex}].daghi.branchId`,
+                partId: part.partId,
+              },
+            ),
           );
         }
       }
@@ -2300,7 +2338,12 @@ export class ExpertClaimService {
   ) {
     const claim = await this.claimCaseDbService.findById(claimRequestId);
     if (!claim) {
-      throw new NotFoundException("Claim request not found");
+      throw new NotFoundException(
+        this.expertReplySubmissionError(
+          "پرونده خسارت یافت نشد.",
+          "CLAIM_NOT_FOUND",
+        ),
+      );
     }
 
     await this.assertExpertActorOnClaim(claim, actor);
@@ -3265,29 +3308,47 @@ export class ExpertClaimService {
     const claim = await this.claimCaseDbService.findById(claimRequestId);
 
     if (!claim) {
-      throw new NotFoundException("Claim request not found");
+      throw new NotFoundException(
+        this.expertReplySubmissionError(
+          "پرونده خسارت یافت نشد.",
+          "CLAIM_NOT_FOUND",
+        ),
+      );
     }
 
     await this.assertExpertActorOnClaim(claim, actor);
 
     if (claim.status !== ClaimCaseStatus.EXPERT_REVIEWING) {
       throw new BadRequestException(
-        `Claim is not in a reviewable state. Current status: ${claim.status}`,
+        this.expertReplySubmissionError(
+          "پرونده در وضعیت قابل بررسی برای ثبت پاسخ کارشناسی نیست.",
+          "CLAIM_NOT_REVIEWABLE",
+          { currentStatus: claim.status },
+        ),
       );
     }
 
     if (!claim.workflow?.locked) {
       throw new ForbiddenException(
-        "You must lock the claim before submitting a reply",
+        this.expertReplySubmissionError(
+          "پیش از ثبت پاسخ کارشناسی باید پرونده را قفل کنید.",
+          "CLAIM_NOT_LOCKED",
+        ),
       );
     }
 
     if (claim.workflow.lockedBy?.actorId?.toString() !== actor.sub) {
-      throw new ForbiddenException("This claim is locked by another expert");
+      throw new ForbiddenException(
+        this.expertReplySubmissionError(
+          "این پرونده توسط کارشناس دیگری قفل شده است.",
+          "CLAIM_LOCKED_BY_ANOTHER_EXPERT",
+        ),
+      );
     }
 
     const pricingValidationError = getExpertReplyPricingValidationError(
       reply.parts,
+      { locale: "fa", enforceAmountBounds: true },
     );
     if (pricingValidationError) {
       throw new BadRequestException(pricingValidationError);
@@ -3305,8 +3366,9 @@ export class ExpertClaimService {
       }
       if (totalPrice > priceCap) {
         throw new BadRequestException({
-          message: `You have reached the maximum acceptable total price (Toman). The sum of priced parts and factor lines (${totalPrice.toLocaleString()}) exceeds the limit (${priceCap.toLocaleString()}).`,
+          message: `مجموع مبلغ قطعات (${totalPrice.toLocaleString("fa-IR")}) از سقف مجاز (${priceCap.toLocaleString("fa-IR")}) تومان بیشتر است.`,
           error: "PRICE_CAP_ERROR",
+          code: "PRICE_CAP_ERROR",
           totalPrice,
           priceCap,
         });
@@ -3337,7 +3399,11 @@ export class ExpertClaimService {
       );
       if (!selected) {
         throw new BadRequestException(
-          `Unknown partId "${p.partId}". Use numeric catalog id from claim detail damagedParts.`,
+          this.expertReplySubmissionError(
+            `قطعه با شناسه ${p.partId} در فهرست قطعات آسیب‌دیده پرونده وجود ندارد.`,
+            "PART_NOT_ON_CLAIM",
+            { field: "partId", partId: p.partId },
+          ),
         );
       }
 
@@ -3355,22 +3421,32 @@ export class ExpertClaimService {
         );
       } catch (err) {
         throw new BadRequestException(
-          `Invalid part ${p.partId}: ${
-            err instanceof Error ? err.message : String(err)
-          }`,
+          this.expertReplySubmissionError(
+            `اطلاعات قطعه ${p.partId} معتبر نیست.`,
+            "PART_INVALID",
+            { field: "partId", partId: p.partId },
+          ),
         );
       }
 
       const catalogId = catalogPartIdFromCarPartDamage(carPartDamage);
       if (catalogId == null) {
         throw new BadRequestException(
-          `Invalid part ${p.partId}: a numeric catalog id is required.`,
+          this.expertReplySubmissionError(
+            `شناسه قطعه ${p.partId} معتبر نیست.`,
+            "PART_ID_INVALID",
+            { field: "partId", partId: p.partId },
+          ),
         );
       }
 
       if (seenCatalogIds.has(catalogId)) {
         throw new BadRequestException(
-          `Duplicate part submitted in expert reply: ${catalogId}.`,
+          this.expertReplySubmissionError(
+            `قطعه ${catalogId} بیش از یک‌بار ارسال شده است.`,
+            "DUPLICATE_PART",
+            { field: "partId", partId: catalogId },
+          ),
         );
       }
       seenCatalogIds.add(catalogId);
@@ -3399,7 +3475,10 @@ export class ExpertClaimService {
 
     if (objectionSubmitted && hasFinalReply) {
       throw new ConflictException(
-        "A final expert reply after objection already exists for this claim.",
+        this.expertReplySubmissionError(
+          "پاسخ نهایی کارشناسی پس از اعتراض، پیش‌تر برای این پرونده ثبت شده است.",
+          "FINAL_REPLY_ALREADY_SUBMITTED",
+        ),
       );
     }
 
diff --git a/src/expert-claim/expert-claim.v2.controller.ts b/src/expert-claim/expert-claim.v2.controller.ts
index 02172be..fcfdb99 100644
--- a/src/expert-claim/expert-claim.v2.controller.ts
+++ b/src/expert-claim/expert-claim.v2.controller.ts
@@ -10,6 +10,7 @@ import {
   Post,
   Put,
   UseGuards,
+  UsePipes,
   Query,
   Res,
 } from "@nestjs/common";
@@ -50,6 +51,7 @@ import {
 import { FactorValidationV2Dto } from "./dto/factor-validation.dto";
 import { ClaimRequestManagementService } from "src/claim-request-management/claim-request-management.service";
 import { OuterPartCatalogItemDto } from "src/claim-request-management/dto/select-outer-parts-v2.dto";
+import { submitExpertReplyValidationPipe } from "./pipes/submit-expert-reply-validation.pipe";
 
 class InPersonVisitV2Dto {
   @ApiPropertyOptional({ example: "Paint damage requires physical inspection" })
@@ -266,7 +268,7 @@ export class ExpertClaimV2Controller {
   @ApiOperation({
     summary: "Submit expert damage assessment reply",
     description:
-      "**Preconditions:** claim locked by this expert (`EXPERT_REVIEWING`). **Unlocks** the claim. Each `parts[]` line needs `partId` (from GET claim detail `damagedParts[].partId`), plus pricing, `daghi`, and optional `factorNeeded`. **Cap:** sum of line `totalPayment` values ≤ 53,000,000 **Toman** (same limit as factor-validation totals across priced + factor lines). Clears any prior `evaluation.ownerInsurerApproval` / `ownerPricedPartsApproval`.\n\n" +
+      "**Preconditions:** claim locked by this expert (`EXPERT_REVIEWING`). **Unlocks** the claim. Each `parts[]` line needs `partId` (from GET claim detail `damagedParts[].partId`), plus pricing, `daghi`, and optional `factorNeeded`. Every supplied monetary field (`price`, `salary`, `totalPayment`, and `daghi.price`) must be 100,000–10,000,000,000 **Toman**. **Cap:** sum of line `totalPayment` values ≤ 53,000,000 **Toman** (same limit as factor-validation totals across priced + factor lines). Clears any prior `evaluation.ownerInsurerApproval` / `ownerPricedPartsApproval`.\n\n" +
       "**Frontend routing by `ClaimCaseStatus` (`status`):**\n" +
       "- **All parts `factorNeeded`:** `OWNER_REPAIR_FACTOR_UPLOAD_PENDING`, `claimStatus=NEEDS_REVISION`, `workflow.currentStep=OWNER_UPLOAD_FACTOR_DOCUMENTS`, `workflow.nextStep=EXPERT_COST_EVALUATION` → owner uploads all factors; then `status` becomes **`EXPERT_VALIDATING_REPAIR_FACTORS`**, `claimStatus=UNDER_REVIEW`, `currentStep=EXPERT_COST_EVALUATION` for expert **validate-factors**.\n" +
       "- **Mixed (some priced, some factorNeeded):** `INSURER_REVIEW_MIXED_FACTORS_PENDING`, `claimStatus=NEEDS_REVISION`, `currentStep=INSURER_REVIEW`, `nextStep=OWNER_UPLOAD_FACTOR_DOCUMENTS` → owner must call **owner-insurer-approval/sign** first (priced-line acceptance); `currentStep` then moves to `OWNER_UPLOAD_FACTOR_DOCUMENTS` (same case `status` until factors are done).\n" +
@@ -276,6 +278,7 @@ export class ExpertClaimV2Controller {
   })
   @ApiParam({ name: "claimRequestId" })
   @ApiBody({ type: SubmitExpertReplyV2Dto })
+  @UsePipes(submitExpertReplyValidationPipe)
   async submitExpertReplyV2(
     @Param("claimRequestId") claimRequestId: string,
     @Body() body: SubmitExpertReplyV2Dto,
diff --git a/src/expert-claim/pipes/submit-expert-reply-validation.pipe.spec.ts b/src/expert-claim/pipes/submit-expert-reply-validation.pipe.spec.ts
new file mode 100644
index 0000000..f722f25
--- /dev/null
+++ b/src/expert-claim/pipes/submit-expert-reply-validation.pipe.spec.ts
@@ -0,0 +1,70 @@
+import { SubmitExpertReplyV2Dto } from "../dto/expert-claim-v2.dto";
+import { TypeOfDamage } from "src/Types&Enums/claim-request-management/type-of-damage.enum";
+import { submitExpertReplyValidationPipe } from "./submit-expert-reply-validation.pipe";
+
+describe("submitExpertReplyValidationPipe", () => {
+  it("converts DTO validation failures into Persian, field-addressable errors", async () => {
+    await expect(
+      submitExpertReplyValidationPipe.transform(
+        { parts: [] },
+        { type: "body", metatype: SubmitExpertReplyV2Dto },
+      ),
+    ).rejects.toMatchObject({
+      response: {
+        code: "EXPERT_REPLY_VALIDATION_ERROR",
+        message: "اطلاعات ارسالی پاسخ کارشناسی معتبر نیست.",
+        validationErrors: expect.arrayContaining([
+          expect.objectContaining({ field: "parts" }),
+        ]),
+      },
+    });
+  });
+
+  it("accepts a reply without a description", async () => {
+    await expect(
+      submitExpertReplyValidationPipe.transform(
+        {
+          parts: [
+            {
+              partId: 201,
+              typeOfDamage: TypeOfDamage.Repair,
+              salary: "100000",
+              totalPayment: "100000",
+              factorNeeded: false,
+            },
+          ],
+        },
+        { type: "body", metatype: SubmitExpertReplyV2Dto },
+      ),
+    ).resolves.toBeInstanceOf(SubmitExpertReplyV2Dto);
+  });
+
+  it("identifies invalid nested price fields for the frontend", async () => {
+    await expect(
+      submitExpertReplyValidationPipe.transform(
+        {
+          description: "Damage assessment",
+          parts: [
+            {
+              partId: 201,
+              typeOfDamage: "repair",
+              salary: "not-a-number",
+              totalPayment: "100000",
+              factorNeeded: false,
+            },
+          ],
+        },
+        { type: "body", metatype: SubmitExpertReplyV2Dto },
+      ),
+    ).rejects.toMatchObject({
+      response: {
+        validationErrors: expect.arrayContaining([
+          {
+            field: "parts[0].salary",
+            message: "باید مبلغ صحیح و غیرمنفی به تومان باشد.",
+          },
+        ]),
+      },
+    });
+  });
+});
diff --git a/src/expert-claim/pipes/submit-expert-reply-validation.pipe.ts b/src/expert-claim/pipes/submit-expert-reply-validation.pipe.ts
new file mode 100644
index 0000000..bb6f6fe
--- /dev/null
+++ b/src/expert-claim/pipes/submit-expert-reply-validation.pipe.ts
@@ -0,0 +1,59 @@
+import {
+  BadRequestException,
+  ValidationError,
+  ValidationPipe,
+} from "@nestjs/common";
+
+type FrontendValidationError = {
+  field: string;
+  message: string;
+};
+
+const constraintMessages: Record<string, string> = {
+  isString: "باید به‌صورت متن ارسال شود.",
+  isNotEmpty: "وارد کردن این فیلد الزامی است.",
+  isArray: "باید به‌صورت فهرست ارسال شود.",
+  arrayMinSize: "حداقل یک قطعه آسیب‌دیده باید ارسال شود.",
+  isBoolean: "باید درست یا نادرست باشد.",
+  isInt: "باید یک عدد صحیح باشد.",
+  isEnum: "مقدار واردشده معتبر نیست.",
+  nestedValidation: "اطلاعات این بخش معتبر نیست.",
+  isMoneyAmountString: "باید مبلغ صحیح و غیرمنفی به تومان باشد.",
+};
+
+function flattenValidationErrors(
+  errors: ValidationError[],
+  parentPath = "",
+): FrontendValidationError[] {
+  return errors.flatMap((error) => {
+    const field = parentPath
+      ? /^\d+$/.test(error.property)
+        ? `${parentPath}[${error.property}]`
+        : `${parentPath}.${error.property}`
+      : error.property;
+    const ownErrors = Object.keys(error.constraints ?? {}).map((constraint) => ({
+      field,
+      message: constraintMessages[constraint] ?? "مقدار واردشده معتبر نیست.",
+    }));
+    return [...ownErrors, ...flattenValidationErrors(error.children ?? [], field)];
+  });
+}
+
+/**
+ * Endpoint-scoped because this application deliberately has no global
+ * ValidationPipe. It preserves DTO validation while returning a stable,
+ * Persian payload that the frontend can render by field.
+ */
+export const submitExpertReplyValidationPipe = new ValidationPipe({
+  transform: true,
+  whitelist: true,
+  exceptionFactory: (errors: ValidationError[]) => {
+    const validationErrors = flattenValidationErrors(errors);
+    return new BadRequestException({
+      message: "اطلاعات ارسالی پاسخ کارشناسی معتبر نیست.",
+      error: "EXPERT_REPLY_VALIDATION_ERROR",
+      code: "EXPERT_REPLY_VALIDATION_ERROR",
+      validationErrors,
+    });
+  },
+});
diff --git a/src/helpers/expert-reply-pricing.spec.ts b/src/helpers/expert-reply-pricing.spec.ts
index 8d2ad04..1a9c093 100644
--- a/src/helpers/expert-reply-pricing.spec.ts
+++ b/src/helpers/expert-reply-pricing.spec.ts
@@ -1,4 +1,8 @@
-import { getExpertReplyPricingValidationError } from "./expert-reply-pricing";
+import {
+  EXPERT_REPLY_MAX_AMOUNT_TOMAN,
+  EXPERT_REPLY_MIN_AMOUNT_TOMAN,
+  getExpertReplyPricingValidationError,
+} from "./expert-reply-pricing";
 import { TypeOfDamage } from "src/Types&Enums/claim-request-management/type-of-damage.enum";
 import { DaghiOption } from "src/Types&Enums/claim-request-management/daghi-option.enum";
 
@@ -121,4 +125,41 @@ describe("getExpertReplyPricingValidationError", () => {
       ]),
     ).toBeNull();
   });
+
+  it.each([
+    ["price", "99,999", "parts[0].price"],
+    ["salary", "10,000,000,001", "parts[0].salary"],
+    ["totalPayment", "99,999", "parts[0].totalPayment"],
+    ["daghi.price", "10,000,000,001", "parts[0].daghi.price"],
+  ])(
+    "enforces the amount range for %s",
+    (field, invalidValue, expectedField) => {
+      const part = {
+        partId: 201,
+        typeOfDamage: TypeOfDamage.Change,
+        price: "100000",
+        salary: "100000",
+        totalPayment: "100000",
+        daghi: {
+          option: DaghiOption.RECYCLED_PARTS_VALUE,
+          price: "100000",
+        },
+      };
+      if (field === "daghi.price") part.daghi.price = invalidValue;
+      else part[field] = invalidValue;
+
+      expect(
+        getExpertReplyPricingValidationError([part], {
+          locale: "fa",
+          enforceAmountBounds: true,
+        }),
+      ).toMatchObject({
+        code: "EXPERT_REPLY_VALIDATION_ERROR",
+        field: expectedField,
+        rule: "amount_out_of_range",
+        minAmount: EXPERT_REPLY_MIN_AMOUNT_TOMAN,
+        maxAmount: EXPERT_REPLY_MAX_AMOUNT_TOMAN,
+      });
+    },
+  );
 });
diff --git a/src/helpers/expert-reply-pricing.ts b/src/helpers/expert-reply-pricing.ts
index c60d1a0..d44f1ee 100644
--- a/src/helpers/expert-reply-pricing.ts
+++ b/src/helpers/expert-reply-pricing.ts
@@ -11,6 +11,34 @@ type ExpertReplyPricingPart = {
   daghi?: { option?: unknown; price?: unknown };
 };
 
+export const EXPERT_REPLY_MIN_AMOUNT_TOMAN = 100_000;
+export const EXPERT_REPLY_MAX_AMOUNT_TOMAN = 10_000_000_000;
+
+export type ExpertReplyPricingValidationError = {
+  message: string;
+  error: "EXPERT_REPLY_VALIDATION_ERROR";
+  code: "EXPERT_REPLY_VALIDATION_ERROR";
+  field: string;
+  partId?: string | number;
+  rule:
+    | "required"
+    | "invalid_value"
+    | "invalid_amount"
+    | "amount_out_of_range";
+  minAmount?: number;
+  maxAmount?: number;
+};
+
+type ValidationOptions = {
+  /** Preserve legacy English strings unless the V2 endpoint explicitly asks for a localized response. */
+  locale?: "fa";
+  enforceAmountBounds?: boolean;
+};
+
+function toPersianAmount(amount: number): string {
+  return amount.toLocaleString("fa-IR");
+}
+
 /**
  * Validates the pricing that an expert must provide for every submitted
  * damaged-part line. This is deliberately independent of DTO validation:
@@ -19,9 +47,33 @@ type ExpertReplyPricingPart = {
  */
 export function getExpertReplyPricingValidationError(
   parts: unknown,
-): string | null {
+  options: ValidationOptions = {},
+): string | ExpertReplyPricingValidationError | null {
+  const localizedError = (
+    message: string,
+    field: string,
+    rule: ExpertReplyPricingValidationError["rule"],
+    partId?: string | number,
+    range?: { minAmount: number; maxAmount: number },
+  ): string | ExpertReplyPricingValidationError => {
+    if (options.locale !== "fa") return message;
+    return {
+      message,
+      error: "EXPERT_REPLY_VALIDATION_ERROR",
+      code: "EXPERT_REPLY_VALIDATION_ERROR",
+      field,
+      ...(partId != null && { partId }),
+      rule,
+      ...(range ?? {}),
+    };
+  };
+
   if (!Array.isArray(parts) || parts.length === 0) {
-    return "At least one damaged part with pricing is required to submit an expert reply.";
+    return localizedError(
+      "برای ثبت پاسخ کارشناسی، حداقل یک قطعه آسیب‌دیده همراه با مبلغ لازم است.",
+      "parts",
+      "required",
+    );
   }
 
   for (const [index, rawPart] of parts.entries()) {
@@ -32,13 +84,22 @@ export function getExpertReplyPricingValidationError(
         : `Damaged part ${index + 1}`;
 
     if (!part || typeof part !== "object" || part.partId == null) {
-      return `${label} must include a damaged-part partId.`;
+      return localizedError(
+        `شناسه قطعه در ردیف ${index + 1} الزامی است.`,
+        `parts[${index}].partId`,
+        "required",
+      );
     }
 
     if (
       !Object.values(TypeOfDamage).includes(part.typeOfDamage as TypeOfDamage)
     ) {
-      return `${label} requires typeOfDamage to be either '${TypeOfDamage.Repair}' or '${TypeOfDamage.Change}'.`;
+      return localizedError(
+        `نوع خسارت قطعه ${String(part.partId)} معتبر نیست.`,
+        `parts[${index}].typeOfDamage`,
+        "invalid_value",
+        String(part.partId),
+      );
     }
 
     const daghi = part.daghi;
@@ -47,7 +108,12 @@ export function getExpertReplyPricingValidationError(
       (!daghi ||
         !Object.values(DaghiOption).includes(daghi.option as DaghiOption))
     ) {
-      return `${label} requires a valid daghi option.`;
+      return localizedError(
+        `گزینه داغی برای قطعه ${String(part.partId)} الزامی و باید معتبر باشد.`,
+        `parts[${index}].daghi.option`,
+        "required",
+        String(part.partId),
+      );
     }
 
     const price = parseMoneyAmountToman(part.price);
@@ -60,21 +126,96 @@ export function getExpertReplyPricingValidationError(
 
     const amountIsValid = (amount: number | null) => amount !== null;
     const priceIsRequired = part.typeOfDamage === TypeOfDamage.Change;
-    const priceIsValid = !hasPrice || amountIsValid(price);
 
-    if (
-      !amountIsValid(salary) ||
-      !amountIsValid(totalPayment) ||
-      (priceIsRequired && !amountIsValid(price)) ||
-      !priceIsValid
-    ) {
+    const requiredAmountFields: Array<[
+      "price" | "salary" | "totalPayment",
+      number | null,
+      boolean,
+    ]> = [
+      ["price", price, priceIsRequired || hasPrice],
+      ["salary", salary, true],
+      ["totalPayment", totalPayment, true],
+    ];
+    const invalidAmount = requiredAmountFields.find(
+      ([, amount, required]) => required && !amountIsValid(amount),
+    );
+
+    if (invalidAmount) {
+      const field = invalidAmount[0] as "price" | "salary" | "totalPayment";
+      if (options.locale === "fa") {
+        const fieldName =
+          field === "price"
+            ? "قیمت قطعه"
+            : field === "salary"
+              ? "دستمزد"
+              : "مبلغ کل";
+        return localizedError(
+          `${fieldName} قطعه ${String(part.partId)} باید به‌صورت مبلغ صحیح و غیرمنفی (تومان) وارد شود.`,
+          `parts[${index}].${field}`,
+          "invalid_amount",
+          String(part.partId),
+        );
+      }
       return `${label} requires valid salary and totalPayment; price is also required for '${TypeOfDamage.Change}' damage. Price, salary, and totalPayment may be 0.`;
     }
 
+    if (options.enforceAmountBounds) {
+      const monetaryFields: Array<[
+        "price" | "salary" | "totalPayment" | "daghi.price",
+        number | null,
+        boolean,
+      ]> = [
+        ["price", price, priceIsRequired || hasPrice],
+        ["salary", salary, true],
+        ["totalPayment", totalPayment, true],
+        [
+          "daghi.price",
+          daghiPrice,
+          daghi?.option === DaghiOption.RECYCLED_PARTS_VALUE,
+        ],
+      ];
+      const outOfRange = monetaryFields.find(
+        ([, amount, required]) =>
+          required &&
+          amount !== null &&
+          (amount < EXPERT_REPLY_MIN_AMOUNT_TOMAN ||
+            amount > EXPERT_REPLY_MAX_AMOUNT_TOMAN),
+      );
+      if (outOfRange) {
+        const [field] = outOfRange;
+        const fieldName =
+          field === "price"
+            ? "قیمت قطعه"
+            : field === "salary"
+              ? "دستمزد"
+              : field === "totalPayment"
+                ? "مبلغ کل"
+                : "قیمت داغی";
+        return localizedError(
+          `${fieldName} قطعه ${String(part.partId)} باید حداقل ${toPersianAmount(EXPERT_REPLY_MIN_AMOUNT_TOMAN)} و حداکثر ${toPersianAmount(EXPERT_REPLY_MAX_AMOUNT_TOMAN)} تومان باشد.`,
+          `parts[${index}].${field}`,
+          "amount_out_of_range",
+          String(part.partId),
+          {
+            minAmount: EXPERT_REPLY_MIN_AMOUNT_TOMAN,
+            maxAmount: EXPERT_REPLY_MAX_AMOUNT_TOMAN,
+          },
+        );
+      }
+    }
+
     if (
       daghi?.option === DaghiOption.RECYCLED_PARTS_VALUE &&
       daghiPrice === null
     ) {
+      if (options.locale === "fa") {
+        return localizedError(
+          `قیمت داغی قطعه ${String(part.partId)} باید به‌صورت مبلغ صحیح و غیرمنفی (تومان) وارد شود.`,
+          `parts[${index}].daghi.price`,
+          "invalid_amount",
+          String(part.partId),
+        );
+      }
       return `${label} requires a valid daghi price when option is '${DaghiOption.RECYCLED_PARTS_VALUE}'.`;
     }
   }