How to create a Custom field in the address form

To add a custom field in the address form

Step1: create other record field:

Goto Customization> List record & Fields> other record field:

E.g.

Step 2:

Go to Goto Customization> forms> Address forms

Customize and create a new form and check the custom field show

Step: 3 Select the country you wish to add this field

and click save