rdpern,
I think I may be misunderstanding something here so I will explain what I know and go from there.
If the user is able to dial a 10-digit number without 1 and it goes through then it is considered a local call or possibly an on-net call if the trunking is SIP; either way it works. As for forcing the carrier to force you to use a 1 on a local or on-net call; most likely isn't happening.
The MiVO-250 requires at least 1 home area code for identifying local calls. It also allows up to 15 additional home area codes. The system refers to these area codes for toll restriction and call cost. Note that the first area code programming behaves differently than the next 15 home area codes. For the first area code programming, the area code digits are stripped from the dialed outgoing number. Other home area codes serve to identify local calls, but are still dialed. If local 10-digit dialing is always required despite the area codes, do not list an area code in the first home area code.
This is located in System > Numbering Plan > Home Area Codes
Now there is the matter of how they setup the Area Flags
Office Codes Used As Area Codes: Yes (Default)
Area Codes Used As Office Codes: Yes (Default)
Local 7/10 Digit Dialing: No (Default)
Toll Digit Allowed On Toll Local Calls: No (Default)
Toll Digit Required On Toll Long Distance: Yes (Default)
The first 2 entries are just so the system can determine end-of-dialing detection based on the NANP and in North American should mostly just be left alone at Yes. Most vendors in North American will also change the Local 7/10 Digit Dialing to Yes as well since the FCC no longer supports 7 Digit Local Call Dialing; even though the local CO may. The remaining 2 entries are also, usually, set to No as well in North America for obvious reasons, but they could leave Toll Digit Required On Toll Long Distance set to Yes, but they users may run into a problem we have in the St. Louis Area where some Area Codes are both Local and Long Distance.
This is located in System > Numbering Plan > Area Flags
Although Magpye is correct that you could setup some custom Class of Services with Deny and Allow rules that would be going a little overboard with the programming; in my opinion. If you were going to do that it would be best to just create a Dial Plan within ARS that inserts the 1 for those calls that you want to have it, but that would a lot of programming as well; I would still be hesitant though.
The reason I would be hesitant to create a lot of programming is that I don't see how this is by-passing a call accounting system. It is the very nature of a call accounting system is to track all the calls regardless if they have are Local, Toll-Free, Long-Distance or International.
What exactly isn't happening that they are blaming the MiVO-250 programming? Are we confusing Account Codes with Call Accounting maybe?
Thanks,
TE