PRI Billing in a Multi Company Setup

I have been reading the “Building Telephone Systems with Asterisk”. I have a similar (almost exact) setup to their Case for Hosted PBX.

I have three tenants in a building who want to use the same phone system. The example setup covers incoming calls and routing them correctly.

My question is on the billing side. It’s a general question on how to determine who makes what calls and how to charge them.

I would think this is something the phone company (AT&T was SBC was Ameritech) could do. I have not talked with them yet (don’t actually have the PRI yet).

Does anyone have experience with this type of setup they would care to share. Is it as simple as passing out the correct caller ID number in the outbound call. Then Ameritech will lump the billing charges on the correct phone number in the bill?

Thanks in advance,

We use separate contexts for each customer. We use MySQL for CDR and have queries that give us the billing information for each customer. You could probably use the standard CDR and import the data into a spreadsheet.