Guide · Registration · For the owner setting up or re-registering the shop's number

Registering your WhatsApp Business app number: dual SIM and eSIM, codes that don't arrive, travelling, porting, a number someone used before, and "Login not available right now"

Registering the shop's number can stall when the code doesn't arrive, the phone has two SIMs, the owner is abroad, the number has just moved to a new carrier, or the screen shows someone else's photo. WhatsApp's own Help Center has an article for each of these. This guide puts them in one place, in plain language.

Published 14 October 2026

What registering needs

WhatsApp's article How to register your phone number says you must register an active number, and that WhatsApp sends a code to confirm you own it. You must be able to receive that code by SMS or phone call. The article lists these requirements:

Your own number: You can only register a phone number you own.
Calls and SMS: You must be able to receive phone calls and SMS on the number you are registering.
Nothing blocking: Call-blocking settings, apps and task killers must be turned off, and you should use the latest version of WhatsApp.
Internet: A working connection through mobile data or Wi-Fi. The article says registration may not work if you're roaming or have a bad connection.
A supported device: Not an unsupported device such as an iPad, and not a jailbroken phone.
One number per app: If you want to use both WhatsApp Business and WhatsApp, you need a different phone number for each app.
A supported number: VoIP numbers, toll numbers the caller doesn't pay for, paid premium numbers and universal access numbers (UAN) are not supported. Landlines are supported only on the WhatsApp Business app.

You select your country and enter the number in full international format, then enter the 6-digit code that arrives by SMS. The article says your carrier may charge for the SMS and calls. It also warns: don't guess the code, or you'll be locked out for a period of time. After registering and setting up your profile, you can create a passkey to protect the account.

The article adds a note on data: by entering your phone number, you authorise your mobile carrier to share data from your account and device with WhatsApp or its service providers, for number verification and fraud prevention.

Dual SIM and eSIM: which number WhatsApp uses

WhatsApp's article About using multiple phone numbers or accounts on WhatsApp says:

One number per account: An account can only be verified with one registered number. You can't add a second number to it.
The number, not the SIM: WhatsApp is tied to the number you registered, not to a SIM card or SIM slot. On a dual-SIM or eSIM phone it uses only the number you verified, and the other line doesn't change which account you're signed in to.
eSIM: Works the same way as a physical SIM. You register with the number linked to the eSIM, with no extra steps.
Swapping the SIM: Removing, replacing or swapping the SIM or eSIM doesn't sign you out automatically. But you need an active SIM or eSIM with your registered number to keep access to the account. To use a different number, change your number in WhatsApp.
A new phone: If your number is eligible, you can verify on the new phone with a 6-digit code WhatsApp pushes to the old phone. Otherwise you verify by SMS, whether the number is on a SIM or an eSIM.
Don't hop between phones: The article says that if you switch your account between devices frequently, at some point you may be blocked from re-verifying it.

Two accounts on one phone

WhatsApp's article How to switch accounts on WhatsApp opens with a note: account switching isn't currently available on the WhatsApp Business app. In WhatsApp, the multiple account feature lets you keep two accounts on one mobile phone, but the second account needs a separate phone number and can only be created from your primary mobile device. The feature works only on mobile devices, not on linked devices.

Our reading

If the owner wants personal WhatsApp and the shop on the same phone, the route these pages leave is two apps with two numbers: WhatsApp for the personal number and the WhatsApp Business app for the shop's number. A dual-SIM or eSIM phone can hold both numbers, and each app uses only the number it verified.

When the code doesn't arrive

WhatsApp's article Can't complete registration lists these checks:

An active SIM: The SIM for the number you are registering is in your phone and can receive SMS or phone calls.
The format: You entered the number correctly, in full international format.
Prepaid balance: On a prepaid line, you have enough balance to receive SMS or phone calls.
Abroad: You must turn on roaming to receive international SMS or calls. The article says roaming might cost extra.
Blockers: Task killers and blockers are turned off.
A weak network: Try another network or place, or turn on Wi-Fi Calling in your phone's settings, which lets calls and texts come over Wi-Fi.
Another way: Tap Need help getting a code? to choose SMS or a call, or tap Call me. In most regions, if voicemail is on, the automated call leaves the code in your voicemail.
Too many guesses: "You have guessed the code too many times" means you have to wait the set amount of time before you ask for another code. The article says there's no way to make this faster.
Your mobile provider: If nothing works, your mobile provider can confirm whether SMS or calls to your number are being blocked or delayed.

Our reading

Work down this list once, calmly. Every extra code request and every wrong guess adds waiting, so checking the SIM, the balance and the number format first avoids waits that only get longer.

Registering while you travel

WhatsApp's article I'm traveling and I can't get my WhatsApp code says roaming or connection problems abroad can stop the code arriving. Its options are:

Turn on roaming: In your phone's settings, so you can receive SMS or calls. Roaming can cost extra.
Check your voicemail: If you chose Call me, the automated system should leave the code in your voicemail.
Email, when re-registering: If you are re-registering and had added an email address to your account, you can get the code by email.
A local number: Otherwise, consider using a local number that can receive a call or SMS.

Our reading

A local number means a separate WhatsApp account, not the shop's. If the shop's number has to stay on WhatsApp while you are away, the simpler plan is not to log out or reinstall while you travel.

Email codes, and what they can't do

WhatsApp's article About email verification codes and resetting two-step verification sets the limits:

Existing accounts only: You can log in with an email code only if you added and verified your email in WhatsApp settings, at your first registration or during two-step verification setup. This applies when you log into your existing account on a new phone.
The SIM still has to be there: An active SIM with the account's number must be in your phone to receive codes by any method, including email.
First registration: If you are registering for the first time, the code comes only by SMS or phone call.
Lost SIM: If you lost the number or SIM, email can't get you in. Ask your mobile provider for a new SIM with the same number, or change your number.
Codes that don't work: Only the most recent email code is valid, codes expire after a short time, and you must enter it on the same device that asked for it.

After porting to a new carrier or SIM

WhatsApp's article About logging in after porting your phone number says porting means moving your number to a new mobile carrier or SIM while keeping the same number. WhatsApp is linked to the number, not the carrier, so your account and chats stay with you.

No new login: You don't need to log in and verify again after porting. You only need to if you log out, or delete and reinstall WhatsApp.
Wait for the network: Codes can't be delivered until the number is active on the new network. Check you have a signal and can receive texts and calls from other people.
Every request lengthens the wait: WhatsApp limits how often you can ask for a code. Each new request makes the next wait longer, and asking again too soon can extend it.
When the timer ends: Choose Call me to get the code by phone call. On a new phone, you can verify with your old phone if your number is eligible and you still have it.

Our reading

Don't log out of the shop's WhatsApp or reinstall it on the day of a port. Leave it alone until the new carrier confirms the number is live.

A number someone used before

WhatsApp's article About seeing your phone number already in WhatsApp says mobile providers often recycle numbers, so the previous owner of your number may have used WhatsApp. It ends with a note: the same verification process is used for WhatsApp Business accounts.

Someone else's photo: If the previous owner's account wasn't deleted, you and your contacts may see their profile photo and About on your number. The article says this does not mean they have access to your account. Only the person with an active SIM for the number can register it.
45 days: WhatsApp treats a number as recycled when an account is unused for 45 days and then reactivated on a new mobile device. It then removes the old account data, such as the profile photo and About.
Clean up: Complete verification, enter your own profile details, leave all groups the number is still in and block unknown contacts.
Their two-step verification: If the previous owner set up two-step verification, you wait a few days after verifying before you can use two-step verification. Separately, the email-code article says that if a new SIM asks for a previous owner's two-step PIN, you wait seven days after registering before you can reset the two-step method.

"Login not available right now"

WhatsApp's article Seeing "Login not available right now" says:

What it means: It may indicate suspicious activity or a violation of WhatsApp's Terms of Service, so you may not be able to finish registering for now.
Not the SIM or the code: It is a temporary hold, unrelated to whether your SIM is active or whether a code arrived.
Retrying: Trying again before the hold ends may start a new wait. There's no way to make it faster, and the hold may happen again on a later attempt.
What to do: Wait, then try to register once rather than repeatedly. If the option is there, tap Contact Us to reach WhatsApp Support. The article also points to the Acceptable use of our services section of the Terms of Service.

Automatic verification, and the Meta Account note

WhatsApp's article About automatic phone number verification says this is only available in limited countries and may not be available to you yet. Where it works, WhatsApp can verify you without you typing a code, in one of these ways:

A code on the phone: A unique code stored on your phone when you first confirmed your number is used again later.
Facebook or Instagram: You can opt in to save verification information for future logins through Facebook or Instagram. WhatsApp says Facebook and Instagram won't save your WhatsApp phone number or use it for any other purpose.
Google backup: With end-to-end encrypted backups on in your Google Account, WhatsApp saves a backup code to Google Cloud, so a reinstall can skip SMS verification.
Your carrier: WhatsApp can work with your phone carrier to check that your device information matches the number you're registering.

WhatsApp's article About adding WhatsApp to your Meta Account says adding WhatsApp to a Meta Account is completely optional, and you can add it or move it out at any time. Under the heading Information used by Meta AI, available only in limited countries, it says Meta AI may use information from the profiles and devices in the same Meta Account, and that this information may also be used to improve AI at Meta. These are WhatsApp's and Meta's statements about their own services.

What this means for your shop

BitByteCore is a verified Meta Tech Provider (since 9 September 2026). This guide repeats WhatsApp's own Help Center as we read it on 14 October 2026, and is not legal advice.

Our reading

Keep the shop's SIM active and topped up, add and verify an email in WhatsApp settings before you need it, and treat every code request as something that makes the next wait longer. Most registration trouble in these pages comes back to the SIM, the network or retrying too fast.

Questions

Can I use personal WhatsApp and the WhatsApp Business app on the same number?

No. WhatsApp says that to use both WhatsApp Business and WhatsApp you need a different phone number for each app.

My phone has two SIMs. Which one does WhatsApp use?

WhatsApp says it is tied to the number you registered, not to a SIM or SIM slot, so it uses only the number you verified.

Can I switch between two accounts inside the WhatsApp Business app?

WhatsApp says account switching isn't currently available on the WhatsApp Business app.

I'm abroad and the code isn't coming. What do I do?

WhatsApp says to turn on roaming (it may cost extra), check your voicemail after choosing Call me, use an email code if you are re-registering and had added an email, or consider a local number.

I ported my number to a new carrier. Do I have to register again?

WhatsApp says no, unless you log out or delete and reinstall. Codes can't arrive until the number is active on the new network.

Why does my new number show someone else's photo?

WhatsApp says the previous owner's account may not have been deleted. It doesn't mean they can access your account. Verify the number and add your own profile details.

What does "Login not available right now" mean?

WhatsApp calls it a temporary hold that may point to suspicious activity or a Terms of Service violation. Wait, then try once; retrying early may start a new wait.

Who is BitByteCore?

BitByteCore is a verified Meta Tech Provider (since 9 September 2026). This guide repeats WhatsApp's own Help Center, and is not legal advice.

Sources

WhatsApp Help Center: How to register your phone number, read 14 October 2026.
WhatsApp Help Center: About using multiple phone numbers or accounts on WhatsApp, read 14 October 2026.
WhatsApp Help Center: How to switch accounts on WhatsApp, read 14 October 2026.
WhatsApp Help Center: Can't complete registration, read 14 October 2026.
WhatsApp Help Center: I'm traveling and I can't get my WhatsApp code, read 14 October 2026.
WhatsApp Help Center: About email verification codes and resetting two-step verification, read 14 October 2026.
WhatsApp Help Center: About logging in after porting your phone number, read 14 October 2026.
WhatsApp Help Center: About seeing your phone number already in WhatsApp, read 14 October 2026.
WhatsApp Help Center: Seeing "Login not available right now", read 14 October 2026.
WhatsApp Help Center: About automatic phone number verification, read 14 October 2026.
WhatsApp Help Center: About adding WhatsApp to your Meta Account, read 14 October 2026.

This guide describes WhatsApp's pages as we read them, and is not legal advice. More plain-language notes like this one are on the guides page.

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