Adding customers, numbers and features is not technically part of the billing run. Check that everything has been entered before the bills are produced, as anything missing will not be billed. Ideally, everything would be entered as sales/connections are made, but it is a good idea to check everything is done before proceeding with the billing run.
If daily CDRs are received, the billing errors can be checked during the month, as any numbers which have not been entered into the platform before they begin passing traffic will show up there.