Which number should your AI agent use? Keep the one in your WhatsApp Business app, or add a dedicated line, and how to move customers if you do

The most important decision in WhatsApp automation is not which tool. It is which number. Since 2025 Meta lets a WhatsApp Business app number share itself with the platform, which changes the answer for most small businesses.

By Ritchie, ReplyKit · Published 5 September 2026 · 6 min read

Option one: keep the number in your WhatsApp Business app

Meta calls this coexistence. You connect the number you already use in the WhatsApp Business app, and both keep working: the app on your phone as before, and the agent through the platform on the same number. Customer messages reach both. The agent replies within seconds; if you reply from the phone, the agent sees that and pauses on that chat. At connection Meta asks whether to share your contacts and up to 180 days of chat history with ReplyKit, so the inbox starts with context rather than empty. In ReplyKit this is the first option under Connect WhatsApp number.

The conditions Meta sets: the number must be in the WhatsApp Business app (not personal WhatsApp), the app must be opened at least every two weeks, other linked devices such as WhatsApp Web are unlinked when you connect, and reminders and broadcasts still go through approved templates. Business verification is not available for a shared number, so the green tick is not either. For a clinic or salon that lives in the Business app, this is the natural choice.

Option two: a dedicated number, and when you need one

A personal WhatsApp number cannot be connected to the platform at all, and Meta's migration guide describes moving a number from the app to a business account as a one-way step that deletes the app account. So if your business runs on the owner's personal WhatsApp, give the agent its own line rather than sacrificing the personal one. A dedicated number is also the cleaner choice when several agents or branches each need their own line, when you want business verification and the display name, or when you would rather the owner's phone stayed out of customer chats entirely.

Getting a second number

• Prepaid SIM. Cheapest and simplest. In Malaysia and Singapore a prepaid SIM costs a few ringgit or dollars a month to keep alive. You only need it for the SMS verification code once; the number then lives on Meta's platform and the SIM can sit in a drawer, kept active.
• Virtual mobile number. From a provider that supports WhatsApp verification. Check that it can receive SMS or a voice call from Meta; some VoIP numbers are refused.
• Landline. Meta can verify by voice call, so an existing office landline works and looks established. The line must be able to receive a call at verification time.
• Meta's test number. Not for customers; it is for trying the platform. Use a real number for the business.

Details on virtual numbers and landlines are in this guide.

Connecting it

1. In ReplyKit, open Agents and choose Connect WhatsApp number.
2. Sign in with the Facebook account that manages your business, or create a business portfolio in the flow.
3. Choose the WhatsApp Business Account or create one, enter the new number, and verify it by SMS or voice call.
4. Meta returns the number to ReplyKit and the agent is live. Send it a test message from your own phone.

Business verification in Meta Business Manager is separate and worth doing in the first week: it raises the messaging limit and unlocks the display name customers see.

Moving customers to the new number

• Update every link. Website button, Google Business Profile chat, Instagram bio, ad links, email signature, the door and the counter. The click-to-chat link format is in links and QR codes.
• Set an away message on the old number. "For bookings and questions, message our new line at ..." with the link. Keep it for three months.
• Tell regulars once. A short personal message from the old number, not a broadcast.
• Keep the old number for relationships. Long-standing customers who prefer the owner can keep that channel; the agent handles the front door.

If you want to move a personal number to the platform

Back up the chats, then use WhatsApp's change-number feature to move the personal account to another SIM so friends keep reaching you, and connect the freed number in ReplyKit as a dedicated line. Do this on a quiet day and update the away message on any other line first. For most small businesses, installing the WhatsApp Business app on the business line and using coexistence is simpler than moving anything.

Frequently asked questions

ReplyKit is an independent product and is not affiliated with or endorsed by Meta or WhatsApp. This article is general guidance for running a small business, not legal, financial or regulatory advice.