diff --git a/modules/invoiceIn/back/methods/invoice-in-due-day/specs/new.spec.js b/modules/invoiceIn/back/methods/invoice-in-due-day/specs/new.spec.js
new file mode 100644
index 0000000000..f2f04b993e
--- /dev/null
+++ b/modules/invoiceIn/back/methods/invoice-in-due-day/specs/new.spec.js
@@ -0,0 +1,51 @@
+const LoopBackContext = require('loopback-context');
+const models = require('vn-loopback/server/server').models;
+
+describe('invoiceInDueDay new()', () => {
+    beforeAll(async() => {
+        const activeCtx = {
+            accessToken: {userId: 9},
+            http: {
+                req: {
+                    headers: {origin: 'http://localhost'}
+                }
+            }
+        };
+        spyOn(LoopBackContext, 'getCurrentContext').and.returnValue({
+            active: activeCtx
+        });
+    });
+
+    it('should correctly create a new due day', async() => {
+        const userId = 9;
+        const invoiceInFk = 6;
+
+        const ctx = {
+            req: {
+
+                accessToken: {userId: userId},
+                headers: {origin: 'http://localhost:5000'},
+            }
+        };
+
+        const tx = await models.InvoiceIn.beginTransaction({});
+        const options = {transaction: tx};
+
+        try {
+            await models.InvoiceInDueDay.destroyAll({
+                invoiceInFk
+            }, options);
+
+            await models.InvoiceInDueDay.new(ctx, invoiceInFk, options);
+
+            const result = await models.InvoiceInDueDay.find({where: {invoiceInFk}}, options);
+
+            expect(result).toBeDefined();
+
+            await tx.rollback();
+        } catch (e) {
+            await tx.rollback();
+            throw e;
+        }
+    });
+});