You cannot use the same tax item in both the line items and the txn tax.

I appreciate you for providing us the in-depth details of your concern, Marat.

You'll encounter this error message if the invoice you have in the Java application may have the same tax item in both line items. To resolve this, just open the invoice and use different items if you're going to use the same tax. Then, import the transaction into QuickBooks again. 

You can also manually enter the transaction in QuickBooks to avoid getting the error message (just like you did on your end). Let's make sure we use the different items if you'll be using them both on the body of the invoice and at the bottom in the Tax box. This will double-tax some of the taxable amounts on the transaction. 

I have articles here that provide details about QuickBooks Web Connector:

• Set up QuickBooks Web Connector
• Fix common Web Connector errors

On the other hand, all third-party integrations in any version require developers' expertise. If you encounter an issue importing the invoice from your Java Application into QuickBooks Desktop QuickBooks and Web Connector, it'll best to post this question to our Intuit Developer Forum.

You'll get an answer from one of the experts handling software integration. They'll be able to guide you through the process and ensure the data are successfully imported without a problem. 

Here's how to reach them:

1. Go to this website: https://help.developer.intuit.com/s/.
2. Choose QuickBooks Desktop.
3. Tap the Ask a Question button.
4. Enter your concern and wait for the answer coming from one of the experts.

Visit our QuickBooks Desktop Articles page for more insights about running your business.

This should point you out in the right direction. I'm just one reply away if you need anything else in running your business in QuickBooks. I'm always here to help.

Thank you for your reply!

I was wondering if you may be able to clarify, you said that my invoice has the same tax item in both line items. I have two items in the invoice, one of them is the type of Inventory Part, the second one if the type of Sales Tax Item. Are these two items are line items? Do you mean that these two items have some sort of tax item as a child relationship? May you provide a screenshot that shows where I can change the tax item in line item?

Thank you for your articles they are very useful

Thank you for your reply!

I was wondering if you may be able to clarify, you said that my invoice has the same tax item in both line items. I have two items in the invoice, one of them is the type of Inventory Part, the second one if the type of Sales Tax Item. Are these two items are line items? Do you mean that these two items have some sort of tax item as a child relationship? May you provide a screenshot that shows where I can change the tax item in line item?

Thank you for your articles they are very useful

I'm here to provide further details about your invoice tax items in QuickBooks Desktop (QBDT), @Marat. This way, you'll be able to determine the actions you need to take care of this.

Let me first clarify the statement about your invoice that has the same tax item in both line items. This means you have an item in QuickBooks called "Sales Tax". Its type should be the Sales Tax Item. Instead, it has another item type.

Yes, you've entered two line items in your invoice which is the inventory and sales tax. They may be using the same item type that's why you've encountered the error. To fix this, you need to use a different item type so you can use them both on your invoice. Let me guide you how.

1. Go to the List menu.
2. Select Item List.
3. Find the sales tax item, then select it to open its details.
4. If in the Type field is Sales Tax Item, close the window. 
5. Go to the Edit menu, then select Preferences.
6. Select the Sales Tax menu, then go to the Company Preferences tab.
7. Select another code in the Your most common sales tax item field.
8. Click OK.

I've attached screenshots below for your reference.

On the other hand, if the item type isn't Sales Tax Item, you'll have to rename it (i.e. SalesTax_Old). Then, you need to create a new one. Just make sure to use the Sales Tax Item as its type.

You can use customized form templates in your invoices in QBDT. This way, you're in control of how they look and what information to include in them. If you wish to learn more about it, kindly refer to this article: Use and customize form templates. It also contains instructions about duplicating, importing, and exporting a template.

I'm also adding this article for the step-by-step guide in fixing any error using a Web Connector in QBDT: Fix common Web Connector errors.

Please let me know if you have other concerns. I'm just around to help. Take care always.

According to documentation

The following information refers to invoices specifically, but it also applies to sales receipts. Generally its best to assign a tax item or tax group item to an invoice and allow QuickBooks to apply the same tax to all taxable items on the invoice. However in some situations multiple tax combinations are required, so this method doesn’t work. In this case one must use techniques to apply the taxes in the invoice itself as line items. Using lines to apply taxes isn’t always straight forward.

So I want to apply the taxes in the invoice as a line item, but I got the error in the title. How to fix it? Please, help

Hello there, Marat.

If you opt to enter the sales tax on the invoice or sales receipt line items, ensure that you don't select the same sales tax at the total section. You can enter a different sales tax that has no rate. This way you can save the invoice without errors. 

If you get the same issue though you've edited your items and setup, I'd suggest getting in touch with us so we can further investigate the cause of the error. 

1. From the Help menu and select QuickBooks Desktop Help.
2. Click Contact Us.
3. Enter a brief description of your concern and then click Continue.
4. Select the best way you'll want to connect with us. 

To ensure that we answer your concerns immediately check out our support hours and types. 

Always know the Community is available 24/7. Just leave a reply below or post again if you have other questions. You take care always and have a great day!

Thank you so much, your screenshot helped me to understand what is going on.

Here is a link to InvoiceAdd method: https://developer.intuit.com/app/developer/qbdesktop/docs/api-reference/qbdesktop/invoiceadd

Which method setts the Tax txn (the one below on your screenshot)

It's good to hear that the screenshot helps you, @Marat.

I want to make sure you're able to create an invoice without any problem. All you need to do is enter a different sales tax that has no rate. 

Here's how: 

1. Go to the Customer tab, then click Create Invoice. 
2. Complete the Item and Amount. 
3. Click the drop-down arrow in the Tax box located in the bottom part. 
4. Hit the New tab. 
5. Complete the needed information, then tap OK. 
6. Press Save and New.

To know more about sales tax, check out this article: How to resolve common sales tax issues. This will provide you steps on how to troubleshoot different issues or unexpected results you may encounter while managing your sales tax in QuickBooks Desktop. 

Let me know if you have any questions. I’ll be here to help. Have a good one!