Quick Answer
If a number will not register for the WhatsApp Business API, the reason is usually that it is still active on the WhatsApp or WhatsApp Business app, that it cannot receive SMS (a landline), that too many code requests triggered a cool-down, or that a two-step verification PIN from an earlier registration is still set. Delete or free the number, request the code by voice call if SMS fails, wait out any cool-down, and reset the PIN if needed.
Last checked October 2026. Meta renames menus and changes review rules often, so treat the steps as the path, and confirm the exact wording on screen against Meta's documentation.
Number Requirements
- You must be able to receive a verification code on the number, by SMS or voice call.
- The number must be able to be in use by one WhatsApp account at a time.
- It should be a number you own and keep, not a temporary or shared virtual number that the carrier may recycle.
- It is better to use a dedicated business number than a founder's personal one.
Symptom to Fix
| Symptom | Cause | Fix |
|---|---|---|
| "This number is already registered" / in use | Active on the regular or Business app | On the phone, delete the WhatsApp account (Settings > Account > Delete account). Wait a short while, then retry. Chat history on that app is lost, so back up first. |
| No SMS arrives | Landline, carrier filtering or a number that cannot receive SMS | Choose the voice call option, or switch to a mobile number. |
| Code arrives but is rejected | Code expired or an older code was used | Use only the latest code, within its validity window. |
| "Too many attempts, try again later" | Cool-down after repeated requests | Stop requesting codes and wait. Meta increases the wait with each attempt. |
| Asked for a six-digit PIN you do not know | Two-step verification set on an earlier registration | Use the PIN you set, or reset it through your WhatsApp Business Account settings or the API. |
| Number registers but you cannot send | Not connected to your WABA or the name is pending | Confirm the number status in WhatsApp Manager; see display name. |
| Number worked and now it does not | Disconnected, flagged or banned | See banned number recovery. |
Can I Keep Using the WhatsApp Business App on the Same Number?
Traditionally, no: moving a number to the API took it off the app. Meta has since introduced onboarding options that let a business run the Business app alongside the API for eligible accounts. Availability depends on country and account, so look for that option in the Meta popup rather than assuming. If you are weighing the two products, read WhatsApp Business app vs API.
Voice Call Verification
- When the popup offers a code, choose Call me instead of SMS.
- Answer from a phone or phone system that can receive the call and listen for the digits.
- For a landline with an IVR or reception menu, make sure the call can be answered directly rather than routed to a menu or voicemail.
After It Registers
- Send a message to the number from a personal phone and confirm it reaches the inbox.
- Set the business profile (name, description, address, website).
- Build opt-in properly before any outbound campaign: WhatsApp opt-in guide.
Frequently Asked Questions
Can I use a landline for the WhatsApp Business API?
Yes, if it can receive the voice call verification. SMS will not work on most landlines.
Will deleting WhatsApp from my phone delete my customers?
It deletes that account's chat history on the app. Export or back up important chats, and move contacts into your CRM first. See contact import in Tenreply.
Can I use a virtual number?
Only if it reliably receives the verification code and you control it long term. Number loss is a common source of outages.
How many times can I request a code?
Meta limits attempts and lengthens the wait after repeated requests. Make one clean attempt rather than many.
Get a Working Number Connected
Tenreply's connect screen takes you through Meta's number registration and OTP step by step. Get started with a number that is ready.
- Connect your number in Tenreply: Meta's Embedded Signup walks you through the WhatsApp Business Account, the number and the OTP in one popup, and Tenreply subscribes the webhook for you. If Meta does not return the IDs, enter them by hand on the same screen.
- WhatsApp API pricing calculator: estimate Meta's charges before you scale.
- Template message previewer: check how a template renders before you submit it.
- Security, changelog and roadmap: what is live today and what is coming.
Back to the full map: Meta, WhatsApp and Instagram integration problems: the complete fix guide.