diff --git a/server/src/api/controllers/Sales/SalesEstimates.ts b/server/src/api/controllers/Sales/SalesEstimates.ts
index 211dfc16f..b6d03b654 100644
--- a/server/src/api/controllers/Sales/SalesEstimates.ts
+++ b/server/src/api/controllers/Sales/SalesEstimates.ts
@@ -7,7 +7,6 @@ import asyncMiddleware from 'api/middleware/asyncMiddleware';
 import SaleEstimateService from 'services/Sales/SalesEstimate';
 import DynamicListingService from 'services/DynamicListing/DynamicListService';
 import { ServiceError } from "exceptions";
-import { Request } from 'express-validator/src/base';
 
 @Service()
 export default class SalesEstimatesController extends BaseController {
diff --git a/server/src/api/controllers/Sales/SalesInvoices.ts b/server/src/api/controllers/Sales/SalesInvoices.ts
index 7951a91cc..ff8216b66 100644
--- a/server/src/api/controllers/Sales/SalesInvoices.ts
+++ b/server/src/api/controllers/Sales/SalesInvoices.ts
@@ -400,6 +400,20 @@ export default class SaleInvoicesController extends BaseController {
           ],
         });
       }
+      if (error.errorType === 'SALE_ESTIMATE_NOT_FOUND') {
+        return res.boom.badRequest(null, {
+          errors: [
+            { type: 'FROM_SALE_ESTIMATE_NOT_FOUND', code: 1200 },
+          ],
+        });
+      }
+      if (error.errorType === 'SALE_ESTIMATE_CONVERTED_TO_INVOICE') {
+        return res.boom.badRequest(null, {
+          errors: [
+            { type: 'SALE_ESTIMATE_IS_ALREADY_CONVERTED_TO_INVOICE', code: 1300 },
+          ],
+        });
+      }
     }
     next(error);
   }
diff --git a/server/src/interfaces/SaleEstimate.ts b/server/src/interfaces/SaleEstimate.ts
index 5c5c7d47e..231c7ba59 100644
--- a/server/src/interfaces/SaleEstimate.ts
+++ b/server/src/interfaces/SaleEstimate.ts
@@ -14,6 +14,7 @@ export interface ISaleEstimate {
   sendToEmail: string,
   createdAt?: Date,
   deliveredAt: string|Date,
+  isConvertedToInvoice: boolean
 };
 export interface ISaleEstimateDTO {
   customerId: number,
diff --git a/server/src/services/Sales/SalesEstimate.ts b/server/src/services/Sales/SalesEstimate.ts
index 12e0971d9..561edf2cd 100644
--- a/server/src/services/Sales/SalesEstimate.ts
+++ b/server/src/services/Sales/SalesEstimate.ts
@@ -98,6 +98,16 @@ export default class SaleEstimateService {
     }
   }
 
+  /**
+   * Validates the given sale estimate not already converted to invoice.
+   * @param {ISaleEstimate} saleEstimate - 
+   */
+  validateEstimateNotConverted(saleEstimate: ISaleEstimate) {
+    if (saleEstimate.isConvertedToInvoice) {
+      throw new ServiceError(ERRORS.SALE_ESTIMATE_CONVERTED_TO_INVOICE);
+    }
+  }
+
   /**
    * Transform DTO object ot model object.
    * @param  {number} tenantId
@@ -181,6 +191,7 @@ export default class SaleEstimateService {
       tenantId,
       saleEstimate,
       saleEstimateId: saleEstimate.id,
+      saleEstimateDTO: estimateDTO,
     });
 
     return saleEstimate;
diff --git a/server/src/services/Sales/SalesInvoices.ts b/server/src/services/Sales/SalesInvoices.ts
index b8c6a4f72..ceff4c9a8 100644
--- a/server/src/services/Sales/SalesInvoices.ts
+++ b/server/src/services/Sales/SalesInvoices.ts
@@ -165,10 +165,10 @@ export default class SaleInvoicesService {
     );
 
     return {
-      ...formatDateFields(omit(saleInvoiceDTO, ['delivered', 'entries']), [
-        'invoiceDate',
-        'dueDate',
-      ]),
+      ...formatDateFields(
+        omit(saleInvoiceDTO, ['delivered', 'entries', 'fromEstimateId']),
+        ['invoiceDate', 'dueDate']
+      ),
       // Avoid rewrite the deliver date in edit mode when already published.
       ...(saleInvoiceDTO.delivered &&
         !oldSaleInvoice?.deliveredAt && {
@@ -213,6 +213,15 @@ export default class SaleInvoicesService {
         saleInvoiceDTO.invoiceNo
       );
     }
+    // Validate the from estimate id exists on the storage.
+    if (saleInvoiceDTO.fromEstimateId) {
+      const fromEstimate = await this.saleEstimatesService.getSaleEstimateOrThrowError(
+        tenantId,
+        saleInvoiceDTO.fromEstimateId
+      );
+      // Validate the sale estimate is not already converted to invoice.
+      this.saleEstimatesService.validateEstimateNotConverted(fromEstimate);
+    }
     // Validate items ids existance.
     await this.itemsEntriesService.validateItemsIdsExistance(
       tenantId,
@@ -232,6 +241,7 @@ export default class SaleInvoicesService {
     await this.eventDispatcher.dispatch(events.saleInvoice.onCreated, {
       tenantId,
       saleInvoice,
+      saleInvoiceDTO,
       saleInvoiceId: saleInvoice.id,
       authorizedUser,
     });
@@ -503,8 +513,8 @@ export default class SaleInvoicesService {
 
   /**
    * Retrieve sale invoice with associated entries.
-   * @param {Number} saleInvoiceId - 
-   * @param {ISystemUser} authorizedUser - 
+   * @param {Number} saleInvoiceId -
+   * @param {ISystemUser} authorizedUser -
    * @return {Promise<ISaleInvoice>}
    */
   public async getSaleInvoice(
@@ -584,7 +594,6 @@ export default class SaleInvoicesService {
       }
     });
 
-    
     return salesInvoices;
   }
 }
diff --git a/server/src/subscribers/SaleInvoices/index.ts b/server/src/subscribers/SaleInvoices/index.ts
index a6ee2848e..72e93d270 100644
--- a/server/src/subscribers/SaleInvoices/index.ts
+++ b/server/src/subscribers/SaleInvoices/index.ts
@@ -26,15 +26,16 @@ export default class SaleInvoiceSubscriber {
    * Marks the sale estimate as converted from the sale invoice once created.
    */
   @On(events.saleInvoice.onCreated)
-  public async handleMarkEstimateConvert({
+  public async handleMarkEstimateConvertOnceInvoiceCreated({
     tenantId,
     saleInvoice,
+    saleInvoiceDTO,
     saleInvoiceId,
   }) {
-    if (saleInvoice.fromEstimateId) {
-      this.saleEstimatesService.convertEstimateToInvoice(
+    if (saleInvoiceDTO.fromEstimateId) {
+      await this.saleEstimatesService.convertEstimateToInvoice(
         tenantId,
-        saleInvoice.fromEstiamteId,
+        saleInvoiceDTO.fromEstimateId,
         saleInvoiceId
       );
     }