diff --git a/src/helpers/querystring-helper.spec.js b/src/helpers/querystring-helper.spec.js
index 1c7378be..4af685d9 100644
--- a/src/helpers/querystring-helper.spec.js
+++ b/src/helpers/querystring-helper.spec.js
@@ -1,4 +1,8 @@
-import { buildQueryStringParameterFromArrayOfComplexObjects, getLineItemQueryString } from '@/helpers/querystring-helper';
+import {
+    buildQueryStringParameterFromArrayOfComplexObjects,
+    getLineItemQueryString,
+    getTaxLineItemQueryString
+} from '@/helpers/querystring-helper';
 
 describe('querystring-helper', () => {
     describe('buildQueryStringParameterFromArrayOfComplexObjects', () => {
@@ -44,4 +48,34 @@ describe('querystring-helper', () => {
             expect(result).toBe('&param[0].partNumber=a&param[1].partNumber=b&param[2].partNumber=c&param[3].partNumber=d&param[4].partNumber=e');
         });
     });
+
+    describe('getTaxLineItemQueryString', () => {
+        it('returns empty query string from empty line items', () => {
+            // Arrange
+            const lineItems = [];
+
+            // Act
+            const result = getTaxLineItemQueryString(lineItems, 'param');
+
+            // Assert
+            expect(result).toBe('');
+        });
+
+        it('returns a query string from line items', () => {
+            // Arrange
+            const a = { partNumber: 'a', laborAmount: 0, sellingPrice: 10, kitPrice: 10 };
+            const c = { partNumber: 'c', laborAmount: 5, sellingPrice: 5, kitPrice: 5 };
+            const b = { partNumber: 'b', laborAmount: 10, sellingPrice: 10, kitPrice: 0, childParts: [c] };
+            const d = { partNumber: 'd', laborAmount: 10, sellingPrice: 10, kitPrice: 10 };
+
+            const lineItems = [a, b, d];
+
+            // Act
+            const result = getTaxLineItemQueryString(lineItems, 'param');
+
+            // Assert
+            // eslint-disable-next-line max-len
+            expect(result).toBe('&param[0].partNumber=a&param[0].laborAmount=0&param[0].sellingPrice=10&param[0].kitPrice=10&param[1].partNumber=b&param[1].laborAmount=10&param[1].sellingPrice=10&param[1].kitPrice=0&param[2].partNumber=c&param[2].laborAmount=5&param[2].sellingPrice=5&param[2].kitPrice=5&param[3].partNumber=d&param[3].laborAmount=10&param[3].sellingPrice=10&param[3].kitPrice=10');
+        });
+    });
 });