# Postpaid Billing and Settings

For subscribers on **Postpaid** profiles, SAS Radius creates an **unpaid invoice** shortly before each subscription period ends, so the subscriber can pay for the next period.

- The invoice appears in [User Invoices](https://help.snono-systems.com/books/sas-radius/page/user-invoices) as type **purchase/postpaid**, **unpaid**, due on the user's expiration date.
- The subscriber pays it in the user portal, or a system administrator marks it paid with **Pay Invoice**.

To turn automatic invoices on and set the timing, grace period and overdue handling, see [Settings → Postpaid Billing](https://help.snono-systems.com/books/sas-radius/page/postpaid-billing).

Postpaid profiles are explained in *Profile Types* (Profiles chapter).