## Documentation Index

Access the complete documentation index at:
https://www.zoho.com/ae/books/kb/llms.txt

Use this file to discover all available documentation pages before proceeding.

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# How do I add the TRN of my customers or vendors?

*   Go to the **Contacts** module on the left sidebar.
*   Click the **\+ New** on the top right corner of the page if you are adding a new contact or select the contact to edit.
*   Under **Other Details** section, select the **Tax Treatment** and enter the contacts **TRN number**.
*   Click **Save**.

![Add TRN](/ae/books/kb/images/taxes/add_trn.png)