How to add trn to supplier and customer's contact while adding new one?

Hi there, accounts-sapient. 

Let me share some insight about TRN and how to add it to the Customer or supplier profile. The TNR "Taxpayer Name Reference." The system uses a unique identifier to track and associate tax-related information with a specific taxpayer or entity.  

The TNR is typically assigned by the tax authority and is used to ensure accurate reporting and compliance with tax regulations. It helps QuickBooks Online organize and link tax-related data to the appropriate customer or supplier in the system. 

In QuickBooks Online, adding the Taxpayer Name Reference (TRN) does not have a specific field or feature to add to the customer's or supplier's profile. However, you can add custom fields to the customer's or supplier's profile to track additional information, including the TNR. But QuickBooks Advanced is not available in international regions.

You may consider using a third-party app that is integrated into QuickBooks. You can visit QuickBooks Online App Store and search the app name on the search bar that integrates with QuickBooks. 

Another workaround is adding the TRN by creating a custom field directly on the transactions. Here's how:  

1. Go to the Gear icon.
2. Choose Custom Form Styles.
3. Select the Invoice template you're using.
4. From the Actions column, click Edit.
5. Pick the Content tab.
6. Select the Header part on the sample invoice. 
7. Then click the Manage custom fields. 
8. Enter the information needed and Save. 

You can read through this article for more detailed information about personalising your sales forms: Customise invoices, estimates, and sales receipts in QuickBooks Online.

Also, I've added these articles to learn more ways to manage your sales forms in QuickBooks: 

• Add, customise, or remove logos on sales forms
• Customise sales forms by location

Please don't hesitate to click the Reply button for other concerns. I'll be right here to help you. Have a great day!