Updated on October 25, 2026
Yes, you can use a landline or a toll-free number with the official WhatsApp Business API. Meta requires the number to be owned by you, to have a country code and an area code, and to be able to receive an SMS or a voice call for verification. Since landlines and toll-free lines don’t receive SMS, verification happens by voice call, and that is where IVR menus, extensions and blocked international calls usually get in the way.
This article covers what Meta’s documentation says about each number type, how voice call verification works and how to prepare a line that sits behind an IVR before you register it. Examples come from Brazil, where toll-free numbers start with 0800, but the rules are the same everywhere.
What Meta requires from a business phone number
The Cloud API phone numbers page lists the requirements. The number must:
- be owned by the business;
- have a country code and an area code (short codes are not supported);
- be able to receive voice calls or SMS;
- not be in use on WhatsApp. If it is, the app account has to be deleted first, or the number has to be onboarded through coexistence when the provider supports it.
There is no requirement for the number to be a mobile line. Meta’s own table of number types covers fixed lines, freephone (toll-free) and VoIP, and shows which verification method works best for each.
| Number type | Code by SMS | Code by voice call | Meta’s note |
|---|---|---|---|
| Mobile | Standard | Standard | Simplest path |
| Fixed line | Not recommended | Standard | Disable call forwarding and IVR |
| Freephone (toll-free) | Not recommended | Standard | Disable call forwarding and IVR |
| VoIP | See Meta’s table | Standard | Keep the app or service online with notifications on |
In practice, for landlines and toll-free numbers the method is the voice call. An automated call reads out the 6-digit code, and someone has to pick up and write it down.
Voice call verification: how it works
After you add the number to the WhatsApp Business Account (through your provider’s Embedded Signup, WhatsApp Manager or the API), you request the code with the VOICE method. On Meta’s Graph API the call looks like this:
curl -X POST "https://graph.facebook.com/v26.0/PHONE_NUMBER_ID/request_code" \
-H "Authorization: Bearer YOUR_TOKEN" \
-H "Content-Type: application/json" \
-d '{ "code_method": "VOICE", "language": "en_US" }'Then you confirm the code you received:
curl -X POST "https://graph.facebook.com/v26.0/PHONE_NUMBER_ID/verify_code" \
-H "Authorization: Bearer YOUR_TOKEN" \
-H "Content-Type: application/json" \
-d '{ "code": "123456" }'If the number is already verified, Meta returns HTTP 400 with error 136024. Check the number’s code_verification_status field before requesting a new code. For this and other codes, see WhatsApp API errors.
Verifying is not the same as registering. After verification, the number still has to be registered on Cloud API with a 6-digit PIN (two-step verification). Meta notes that adding a number in the dashboard or in WhatsApp Manager does not register it for Cloud API, and that the number can only send and receive messages once its status is CONNECTED.
Toll-free numbers and IVR: the usual blocker
Meta’s documentation is direct about 1-800 and toll-free numbers: they are usually behind an Interactive Voice Response (IVR) system, and the WhatsApp registration call cannot navigate an IVR. It won’t press “1 for sales” or dial an extension. Numbers behind an IVR can be registered, but they must accept calls from international numbers. Numbers that can’t receive the registration call are not supported.
That means three practical changes before you request the code:
- Turn the IVR off temporarily, or add a rule so incoming calls go straight to a person or a handset during verification.
- Allow inbound international calls. Ask your carrier whether the toll-free number accepts calls that originate outside the country. Some toll-free plans restrict where calls can come from.
- Disable call forwarding and voicemail, which Meta’s table also recommends for fixed and toll-free lines.
Once the number is CONNECTED, the IVR can go back to normal. Registering the number on the API does not affect voice calls on the line: your carrier keeps delivering calls as before. What changes is that the number now exists on WhatsApp through the API.
Extensions and PBX systems
An extension is not a phone number with an area code. It only exists inside the PBX. So:
- You can’t register an extension on the API. You register the external number (the trunk number or a DID, direct inward dialing number).
- If the company has DIDs, each direct number is a full phone number and can in principle be registered, as long as it receives the verification call without going through an IVR.
- If every call comes in through the main number and hits a menu, program the PBX so that, during verification, the call rings straight to a handset someone will answer.
One point that often surprises teams: on WhatsApp, agents don’t sit “on extensions”. Several agents use the same number at the same time through your support platform, because the API is accessed by software, not by a handset. See multiple agents on one number.
Landline, toll-free or mobile: which to choose
| Criterion | Landline | Toll-free | Dedicated mobile |
|---|---|---|---|
| Customer recognition | The number already on your website and storefront | Known customer service number | New number you need to publicize |
| Verification | Voice call | Voice call, with IVR and international calls sorted out | SMS or voice call |
| Setup risk | Forwarding and voicemail | IVR and call origin restrictions | Low |
| Using the WhatsApp Business app at the same time | Only with coexistence | Only with coexistence | Only with coexistence |
If your landline is already printed on invoices, your website and your ads, registering that same number on WhatsApp saves customers from saving yet another contact. A toll-free number has the same benefit for customer service teams, with the extra IVR work.
Whatever the line type, customers see the display name you set up, and it goes through Meta’s review. The rules are in display name on the WhatsApp API.
Phone number limits per business portfolio
Before registering the landline of every branch, check the limit. According to the same Meta page, a new business portfolio can register up to 2 numbers. The cap rises to 20 once the business is verified or the portfolio reaches a messaging limit of 2,000. If you run several locations, get business verification done first.
Checklist for registering a landline or toll-free number
- The number belongs to the business and has an area code.
- The number is not in use on any WhatsApp app, or you will use coexistence. See how to free up a number already on WhatsApp.
- IVR, call forwarding and voicemail are off during verification.
- The line accepts inbound international calls.
- Someone is next to the handset to write down the spoken code.
- The display name follows Meta’s rules.
- You chose and stored the 6-digit PIN used for registration.
How to do it with Vectalk
At Vectalk, you connect a number through Meta’s Embedded Signup inside the dashboard. For numbers that need voice verification, the Vectalk API exposes the same steps as Meta: POST /phone-numbers/request-code with "code_method": "VOICE", POST /phone-numbers/verify-code and POST /phone-numbers/register with the PIN, all authenticated with the instance token. Details are at docs.vectalk.com.br. Vectalk runs on the official Cloud API and pays Meta for you. To get started, create your account, or read how to get access to the WhatsApp API first.
Frequently asked questions
Can I use the landline that already takes the company’s calls?
Yes. Voice calls keep working through your carrier. What changes is that the number now exists on WhatsApp through the API, and it can’t be used on the regular WhatsApp (Messenger) app at the same time.
Does SMS verification work on a landline?
Meta marks SMS as “not recommended” for fixed and toll-free lines. Use voice call verification (VOICE).
Can I register a specific extension?
No. An extension has no area code and doesn’t exist outside the PBX. Register the external number (trunk or DID) and route the verification call to a handset someone answers.
Can I turn the IVR back on after registration?
Yes. The IVR only gets in the way of the verification call. Once the number’s status is CONNECTED, voice calls follow whatever flow you set up with your carrier.
Can a landline use coexistence with the WhatsApp Business app?
Coexistence requires the number to already be active on the WhatsApp Business app, and Meta’s documentation doesn’t restrict the line type for it. If your landline already runs on the app, coexistence saves you from deleting the account. See what syncs with coexistence.
Official sources checked on October 25, 2026: Cloud API phone numbers, Two-step verification, Migrate an existing WhatsApp number to a business account, Onboarding WhatsApp Business app users (coexistence), Vectalk API documentation.