# Billing and Statistics

Billing statistics are tabulated for existing mailboxes on demand by a gather, the same as for any regular mailbox. This characteristic of mailboxes on demand and gather with respect to regular billing procedures has two effects that you should be aware of:

- NP OnDemand mailboxes that are active when the gather is run are included in the billing report.

- NP OnDemand mailboxes that have been purged are not included in the billing report.