A VoIP book is a customer list with a monthly habit

Hosted PBX, SIP trunks and small-business voice seats are bought by operators who already run the stack. They will ask about churn, number portability and how much of the support still sits in your head.

VoIP businesses often look thin on a balance sheet and fat in recurring billings. That gap is why a formal campaign can miss the point. A private buyer who already wholesales voice will price the seats, not the office fit-out.

If you also sell UCaaS or sit beside a CCaaS product, say so. Those files sometimes belong together; sometimes they should be split.