WhatsApp has mentioned a few steps that you can follow if your smartphone is lost or stolen to stop other people from being able to access your WhatsApp account. — AFP
You might be using WhatsApp on the laptop or your PC via the browser or the desktop app, but the messaging platform only works when the primary device, in this case, your smartphone, is connected to the Internet and is turned on. So, if you lose your phone or it gets stolen, you will not be able to use the messaging app anywhere else.
WhatsApp has mentioned a few steps that you can follow if your smartphone is lost or stolen to stop other people from being able to access your WhatsApp account. Keep in mind that remote deactivation of the WhatsApp account is not possible so you need to make sure you follow these steps.
What you must to recover/deactivate your WhatsApp if your smartphone is stolen or lost
1. First things first, lock your SIM card. For this, you need to call your network provider and get them to lock it. What this does is makes it impossible to verify the connected WhatsApp account on that phone again since you will no longer be able to receive SMSs or calls for verification.
2. Once the SIM is locked, you have two options. You can either use a new SIM card with the same number to activate your WhatsApp on a new phone. This is the easiest and fastest way to deactivate your account on the stolen/lost device since WhatsApp can only be activated with one phone number one device at a time.
3. The second option is to deactivate your WhatsApp account without the SIM card. For that you need to email WhatsApp with the phrase "Lost/Stolen: Please deactivate my account" in the body of the email and you need to include your phone number in full international format — which is to use +91 as a prefix for Indian numbers.
4. Once you have deactivated your account, all your WhatsApp contacts can still see your profile and send you messages and this will remain "pending" for up to 30 days. If you manage to reactivate your account within 30 days, you will receive all the messages and will still be a part of all the WhatsApp groups. If you cannot activate your account within 30 days, it will be deleted in its entirety.
If your SIM card is locked, you can still use WhatsApp with your WiFi connection if you have not contacted WhatsApp to deactivate your account. We suggest you do this only if you have managed to recover your device and only after you have deactivated your SIM. This method of using WhatsApp on WiFi is only a temporary solution, you can use it this way as a stop-gap till you don't get a new device or reactivate your SIM.
Also, if you have backed up your WhatsApp data on Google Drive, iCloud, or OneDrive before you lost your device or it got stolen, you will be able to recover all your chat history and all media. – Hindustan Times/TNS
