## Documentation Index

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

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

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# I want to associate a unique number with my customer. How can I do this in Zoho Books?

To enable Customer / Vendor number:

1.  Click the **Settings** icon at the top right corner.
2.  Choose _Customers and Vendors_ from **Preferences**.
3.  Scroll down and mark the checkbox for **Enable Customer Number** to activate the option for customers, and mark the checkbox for **Enable Vendor Number** to activate the option for vendors.

Now, you can opt for any one of the options:

*   **Retain existing vendor / customer numbers**: If you’ve maintained customer / vendor numbers using a custom field until now, you can choose to copy the existing numbers to the new Customer / Vendor Number field.
*   **Generate new vendor / customer numbers**: You can configure a series to generate customer / vendor numbers automatically for all your existing customers or vendors.

4.  Save the preference.

**Note:** Generating these numbers may take a few minutes to a few hours, depending on the number of records that you have. The Vendor Number field will be available once this process is done.

**Warning:** Once you’ve enabled this feature, you cannot disable it.

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