WhatsApp Business API
Number Verification Guide
Number verification is the step where Meta confirms you own the phone number you want to use on the WhatsApp Business API, by sending a one-time code via SMS or voice call. Here's exactly how it works, and how to fix it when the OTP verification fails.
By QuickMessage Team · Last updated
How WhatsApp Number Verification Works
Add your number in Meta Business Manager
During WhatsApp Business API onboarding, you (or QuickMessage on your behalf) enter the phone number you want to use, along with your business display name.
Choose SMS or voice call for the OTP
Meta sends a one-time verification code to that number, either by text message or an automated voice call — voice is typically used for landline or virtual numbers that can't receive SMS.
Enter the code to confirm ownership
You enter the code you received within the time limit shown. This confirms you control the number, which is required before Meta will let you send messages from it.
Number is verified and ready for the API
Once verified, the number is registered to your WhatsApp Business Account (WABA) and ready to send and receive messages through the API — the display name may take a few hours to be separately approved by Meta.
Why Does OTP Verification Fail?
These are the most common reasons WhatsApp Business API verification doesn't go through on the first try.
✕ The number is still active on the regular WhatsApp app
This is the single most common cause. A number can't be registered on the standard WhatsApp app or WhatsApp Business app and the API at the same time. You (or your provider) need to delete the account on the app first — see our full setup guide for the migration steps.
✕ The code expired before you entered it
OTP codes are time-limited. If you wait too long, request a new code rather than trying an old one — it will not work.
✕ SMS didn't arrive on a landline or virtual number
Landlines and some virtual/IVR numbers can't receive SMS. Switch to the voice call OTP option instead of retrying SMS.
✕ Too many failed attempts triggered a temporary cooldown
Repeated incorrect entries can trigger a short waiting period before Meta allows another attempt. If this happens, wait before retrying rather than requesting codes repeatedly.
✕ Number formatting is incorrect
Make sure the number is entered in full international format, including the country code, without spaces or leading zeros.
Still stuck? QuickMessage's onboarding team handles verification for you as part of setup — you don't have to troubleshoot this alone.
Verification
Frequently Asked Questions.
Can I use a number that's already on WhatsApp?
Yes, but the account on the standard app or WhatsApp Business app must be deleted first before that number can be verified for the API.
How long does verification take?
The OTP step itself takes minutes. The overall business verification process (confirming your Meta Business Manager) typically takes 24-48 hours depending on documentation.
Can I verify a toll-free or landline number?
Yes, using the voice call OTP option instead of SMS, since these number types typically can't receive text messages.
What if I never received the OTP at all?
Double-check the number format (including country code), confirm the number can receive SMS or calls, and try the alternate delivery method (voice instead of SMS, or vice versa) before requesting another code.
Skip the Troubleshooting.
Let Us Set It Up For You.
QuickMessage's onboarding team handles number verification and business approval as part of setup.