I had the same arrangement when I had a BBS in the late '90s. At the time my phone was "measured [outgoing] service". Whoever the telco was at that time (NWBell? USWest? Qwest?) told me that I couldn't have one "unlimited" line and still keep measured service on the other. It didn't become an issue until I added another line for the BBS, and had "forward on busy" to a third BBS line. The first phone bill was a shocker, I was charged outgoing charges on line#2 (the BBS line) for every call that got forwarded to line#3 (the second BBS line).
IIRC the solution (arrived at with a cooperative "home office" rep) was to go to unlimited service and drop the (extra cost) "forward on busy" option, replacing it with a (no-charge) "hunt group". I don't know what was technically different on their side, on my side it was exactly the same, except that calls from my home phone were no longer timed, and the base bill was a few bucks higher.
Dave
[TELECOM Digest Editor's Note: Lisa Hancock is confused on this: She needs to remember this is 2007 'anything goes with any telco', _NOT_ 1974-75 'we run it all' Bell. The service reps in those days were very explicit: if two or more phones in the same residence, they all had to have the same type of service. Otherwise, for the subscriber, it would be 'too easy' to 'accidentally' use the phone line which was more generous.The same situation occurred for me in 1978: I worked for an apartment building; the building 'office' had a seldom-used phone which (to save expenses, etc) had an 'answer only' phone tied into the manager's apartment phone so he could answer the phone when he was down in the office (not often). Bell insisted it could not have a dial as an extension phone and still be on residential rates. It was to be for his convenience in _answering_ his own (residential rate) phone in his upstairs apartment only.
We put in an 'Enterphone system' (Bell-supplied front door answering and opening system. It rang in the manager's upstairs apartment, but in the downstairs office it only rang; you could not manipulate the front door from there as a result of no-dial on the phone. I swapped out that (non-dial) phone for one with touch-tone. Miss Prissy just about soiled her panties when she heard what had been done; a touch-tone (gasp!) on a residential-based phone terminated in an office! Albiet seldom used office or extension phone. She demanded it be taken out and replaced with a non-dial extension. Telco repair man told her it was _also being used_ for door answering where phones were supplied _for free_ as needed in spaces which were not normally rented to tenants. Miss Prissy, after due consultation, decided that the 'Enterphone' tariff would prevail instead of the 'no dial on an extension located in a business on residential rates' tariff. This was
1978 after all, Lisa, not 2007. PAT]