---
title: "Fetching Values From Master"
space: "ERPNext"
url: "https://docs.frappe.io/erpnext/fetch-values-from-master"
updated: "2026-03-02"
---


To pull a value of a link on selection, use the `add_fetch` method.

 
 
 add_fetch(link_fieldname, source_fieldname, target_fieldname)
 

### Example

Let' say you have created a Custom Field **VAT ID** (`vat_id`) in **Customer** and **Sales Invoice** and want to make sure that this value gets updated every time you select a Customer in a Sales Invoice.

To configure this, in the Sales Invoice Custom Script, you can add this line:

 
 
 cur_frm.add_fetch('customer','vat_id','vat_id')