Short answer
Open WhatsApp on your own phone and register your number again with the 6-digit code sent by SMS. WhatsApp says this is the only way to remove someone else, and it logs every other device out of the account. If the attacker set a two-step verification PIN you don’t know, you may have to wait before you can register without it. Meanwhile warn your contacts from another channel, never share the 6-digit code with anyone, and once you are back in, check Linked devices and turn on two-step verification yourself.
How WhatsApp accounts get taken over
- The 6-digit code trick: someone — often a hijacked friend’s account — asks you to forward a code “sent by mistake”. It is your registration code.
- Linked devices: a WhatsApp Web or desktop session opened on a computer you left logged in, or via a QR code you were tricked into scanning.
- Voicemail and SIM attacks: the code is requested by voice call and read from an unprotected voicemail box, or the number itself is moved to a new SIM.
Step 1: register your number again
- Open WhatsApp on your phone with your SIM inside and verify your number with the SMS code.
- Every device logged into the account is signed out — including the attacker’s.
- Changing a password or PIN on its own does not remove the other person; registration does.
- If WhatsApp asks for a two-step PIN you never set, the attacker set it. Follow the reset option on screen; WhatsApp may make you wait before the number can be registered without the PIN.
Step 2: limit the damage
- Tell family, friends and group admins that messages from your number may not be from you — hijacked accounts ask contacts for money or for their own codes.
- Screenshot any scam messages sent in your name.
- If your SIM stopped working, contact your mobile operator first: the number has to be yours again before WhatsApp can be.
Step 3: lock it down
- Turn on two-step verification (Settings → Account) with a PIN and a recovery email.
- Check Linked devices and log out of anything you don’t recognise.
- Set a PIN on your voicemail and ask your operator about SIM-swap protection.
- Never share the 6-digit code — WhatsApp will not ask you for it in a chat.
Hacked or banned?
If the screen says your number is banned, nobody took it over — WhatsApp restricted it, and the route is the review request in the app: see WhatsApp account banned. When re-registration fails or the number itself is in someone else’s hands, our hacked account recovery service works the official routes with you.
Frequently asked questions
Can someone use my WhatsApp without my phone?
Yes, through a linked device such as WhatsApp Web, or by registering your number elsewhere with a code you were tricked into sharing. Re-registering on your phone ends both.
Will I lose my chats if I re-register?
Chats stored on your phone stay there, and a backup tied to your number can be restored. Messages never reach a device that was logged out.
Does changing my PIN remove the hacker?
No. WhatsApp says registering again with the 6-digit code is what removes someone else from your account.
The hacker is asking my contacts for money. What now?
Warn them from another channel straight away and ask them to report the messages. Keep screenshots in case you need to report it to the police.
Sources: WhatsApp Help Center — recover a compromised account