[~countrdd] - Could you not assign the customer to a Rate Group which contains Origination Rates at zero cost for those destinations? If not, please explain why so we can better understand your request?

The main reason, is the way rate groups work., they are not stackable. You can only assign a customer to 1 rate group. So that would be a crazy amount of rate groups to maintain.

My plans are

Standard (Local Free, Charged for Non Local Calls, NO INTERNATIONAL DIALING)
FREELD (Free Local and Long-distance (up to 5000 MOUS)
International (Local Free, Charged for LD and International)
InternationalFreeLD (Local Free, Free LD, charged for inernational).

So those would have to be duplicated for every Rate center to include the Free Local Calling.

Honestly, one thing that would really be nice is stackable rate groups, i.e. like an Access Control list in networking, that you prioritize on a customer level.

Ah, so your customers might all have free "local" calls, but the "local" may be different for different customers?

Could you do this with a Package? Each Package allows up to 35,791,394 mins to whichever rates are allowed. While still having to maintain the packages, each Package contains only the rates you want to include so is much smaller than having to maintain a complete duplicate of the Rate Group. Unfortunately I'm still a little hazy on the exact details of packages, but I do know that the counters currently have to be reset manually as this is not part of the invoice process (yet). I may well write this in in the coming weeks / months.

I agree with your view that stackable rates would be good - and I think there is some provision in the DB for this, but I don't think it's written into the code yet. Certainly with only a few Rate Groups, and ~71,000 rates per group duplicating them is not a great option as the system grows.