What this setting controls
Custom customer ID enables an additional ID field on each customer profile so you can store your own internal identifier (membership number, employee number, etc.). The custom ID becomes searchable in the customer table and is included in exported reports. It is admin-only and never shown in the customer-facing app.
How to enable
Go to Admin → Settings → Customer → Enable custom ID. Turn the toggle on and save. From then on, every customer profile shows a Custom ID input you can fill in.
