diff --git a/server/src/api/controllers/Sales/SalesEstimates.ts b/server/src/api/controllers/Sales/SalesEstimates.ts
index 14beda35c..c8573c56c 100644
--- a/server/src/api/controllers/Sales/SalesEstimates.ts
+++ b/server/src/api/controllers/Sales/SalesEstimates.ts
@@ -413,11 +413,6 @@ export default class SalesEstimatesController extends BaseController {
           errors: [{ type: 'NOT_SELL_ABLE_ITEMS', code: 800 }],
         });
       }
-      if (error.errorType === 'SALE_ESTIMATE_ALREADY_APPROVED') {
-        return res.boom.badRequest(null, {
-          errors: [{ type: 'CUSTOMER_NOT_FOUND', code: 900 }],
-        });
-      }
       if (error.errorType === 'SALE_ESTIMATE_ALREADY_APPROVED') {
         return res.boom.badRequest(null, {
           errors: [{ type: 'CUSTOMER_NOT_FOUND', code: 1000 }],
@@ -443,6 +438,16 @@ export default class SalesEstimatesController extends BaseController {
           errors: [{ type: 'SALE_ESTIMATE_NO_IS_REQUIRED', code: 1400 }],
         });
       }
+      if (error.errorType === 'SALE_ESTIMATE_CONVERTED_TO_INVOICE') {
+        return res.boom.badRequest(null, {
+          errors: [{ type: 'SALE_ESTIMATE_CONVERTED_TO_INVOICE', code: 1500 }],
+        });
+      }
+      if (error.errorType === 'SALE_ESTIMATE_ALREADY_DELIVERED') {
+        return res.boom.badRequest(null, {
+          errors: [{ type: 'SALE_ESTIMATE_ALREADY_DELIVERED', code: 1600 }],
+        });
+      }
     }
     next(error);
   }
diff --git a/server/src/services/Sales/Estimates/constants.ts b/server/src/services/Sales/Estimates/constants.ts
index 3e4b4287d..2b58c74a8 100644
--- a/server/src/services/Sales/Estimates/constants.ts
+++ b/server/src/services/Sales/Estimates/constants.ts
@@ -1,3 +1,16 @@
+
+export const ERRORS = {
+  SALE_ESTIMATE_NOT_FOUND: 'SALE_ESTIMATE_NOT_FOUND',
+  SALE_ESTIMATE_NUMBER_EXISTANCE: 'SALE_ESTIMATE_NUMBER_EXISTANCE',
+  SALE_ESTIMATE_CONVERTED_TO_INVOICE: 'SALE_ESTIMATE_CONVERTED_TO_INVOICE',
+  SALE_ESTIMATE_NOT_DELIVERED: 'SALE_ESTIMATE_NOT_DELIVERED',
+  SALE_ESTIMATE_ALREADY_REJECTED: 'SALE_ESTIMATE_ALREADY_REJECTED',
+  CUSTOMER_HAS_SALES_ESTIMATES: 'CUSTOMER_HAS_SALES_ESTIMATES',
+  SALE_ESTIMATE_NO_IS_REQUIRED: 'SALE_ESTIMATE_NO_IS_REQUIRED',
+  SALE_ESTIMATE_ALREADY_DELIVERED: 'SALE_ESTIMATE_ALREADY_DELIVERED',
+  SALE_ESTIMATE_ALREADY_APPROVED: 'SALE_ESTIMATE_ALREADY_APPROVED'
+};
+
 export const DEFAULT_VIEW_COLUMNS = [];
 export const DEFAULT_VIEWS = [
   {
diff --git a/server/src/services/Sales/SalesEstimate.ts b/server/src/services/Sales/SalesEstimate.ts
index b43036330..0091049dd 100644
--- a/server/src/services/Sales/SalesEstimate.ts
+++ b/server/src/services/Sales/SalesEstimate.ts
@@ -22,8 +22,8 @@ import { ServiceError } from 'exceptions';
 import CustomersService from 'services/Contacts/CustomersService';
 import moment from 'moment';
 import AutoIncrementOrdersService from './AutoIncrementOrdersService';
-import { ERRORS } from './constants';
 import SaleEstimateTransformer from './Estimates/SaleEstimateTransformer';
+import { ERRORS } from './Estimates/constants';
 
 /**
  * Sale estimate service.
@@ -355,26 +355,20 @@ export default class SaleEstimateService implements ISalesEstimatesService{
       tenantId,
       estimateId
     );
-
     // Throw error if the sale estimate converted to sale invoice.
     if (oldSaleEstimate.convertedToInvoiceId) {
       throw new ServiceError(ERRORS.SALE_ESTIMATE_CONVERTED_TO_INVOICE);
     }
-
-    this.logger.info(
-      '[sale_estimate] delete sale estimate and associated entries from the storage.'
-    );
+    // Delete sale estimate entries.
     await ItemEntry.query()
       .where('reference_id', estimateId)
       .where('reference_type', 'SaleEstimate')
       .delete();
 
+    // Delete sale estimate transaction.
     await SaleEstimate.query().where('id', estimateId).delete();
-    this.logger.info('[sale_estimate] deleted successfully.', {
-      tenantId,
-      estimateId,
-    });
 
+    // Triggers `onSaleEstimatedDeleted` event.
     await this.eventDispatcher.dispatch(events.saleEstimate.onDeleted, {
       tenantId,
       saleEstimateId: estimateId,