How to Put WhatsApp on a Landline or UAN Number

Most businesses we onboard in Pakistan arrive assuming WhatsApp needs a mobile number, and quietly register a staff member's personal SIM. Then that person leaves, and the company's WhatsApp history leaves with them. The number that should have been used was sitting on the invoice the whole time — the UAN.

A landline, PTCL line or UAN can run WhatsApp Business. Meta supports fixed-line numbers on the WhatsApp Business Platform; the difference is that verification happens by voice call rather than SMS. This page covers the exact requirements Meta publishes, the one that trips up almost every UAN, and when a landline is genuinely the wrong choice.

Is a landline actually supported?

Yes — with a caveat worth stating honestly. In Meta's own phone-number documentation, fixed lines are supported but are not the recommended number type. For SMS one-time passwords they are listed as "Not Recommended"; for voice one-time passwords they are listed as "Standard".

In practice that means: do not try to verify a landline by SMS. Choose the voice option, and Meta rings the line and reads a six-digit code aloud.

The four requirements Meta publishes

These are the conditions a fixed line has to meet. Three of the four are configuration on your side, and they are the whole difference between a verification that works and one that silently fails.

One more trap in the same family: extensions cannot be used. Register the base number, not an extension behind it. If your switchboard is 111-xxx-xxx and sales is extension 204, the number you register is the switchboard.

How to connect it

1. Pick the number — a UAN, PTCL line or landline without an extension, and confirm it is not already registered on WhatsApp.
2. Open the line up: enable international incoming calls, and temporarily disable call forwarding and the IVR.
3. Start registration in WABPO and choose voice verification rather than SMS.
4. Answer the call. An automated voice reads a six-digit code; enter it.
5. Restore your IVR and start answering from the shared inbox — voice calls on the line continue as before.

Why use the landline at all

Because it is already everywhere. The UAN is printed on packaging, invoices, the signboard, the vehicle livery and whatever directory listing you paid for years ago. Putting WhatsApp on it converts every one of those into a messaging entry point without reprinting anything.

The second reason matters more over time: a company number belongs to the company. When WhatsApp lives on a salesperson's personal SIM, so does the customer history — and both walk out together when that person resigns.

When a landline is the wrong choice

Worth saying plainly, because it will save some readers a frustrating afternoon. Meta does not recommend fixed lines, and there are cases where a mobile number is simply the better answer: if you cannot get IVR disabled even briefly, if the line is shared with a switchboard nobody controls, or if international incoming calls are barred by a policy you cannot change. In those situations a dedicated mobile number is faster and less brittle, and there is no prize for insisting on the landline.