Do I have to change my business phone number to use an AI receptionist?

No. You do not have to switch numbers. There are two common options for a business that wants to keep the number it has used for years.

1. Forward calls to a Votel number. Leave the number where it is and set call forwarding to a number in Votel that is connected to your AI agent. You can forward every call, only after hours, or only calls you do not answer. This is the easiest way to get started.
2. Port the number into Votel, then use the agent's call forwarding step to ring the business first and let the AI answer when nobody picks up.

For forwarding only unanswered calls, every carrier has conditional call forwarding codes you dial on the business phone. You type the code with the destination number, and if the call is not answered after a set number of seconds, it goes to your AI receptionist or AI voicemail. Ask which phone company the business uses, or search for that carrier's conditional call forwarding codes. Owner operators who use a cell phone can do the same.

Forwarding calls needs no new A2P (SMS) registration, because AI voice only needs the call to reach Votel, and you can be up and running in about sixty seconds. Either way, the number the AI answers must be forwarded to Votel or live in Votel. Moving only the texting of a number (rehoming SMS) is possible but not common.