
One of the things to do in case the phone has been lost or stolen is to block the account of WhatsApp. In this case, the first step is call the mobile operator and ask them to block the SIM card.
After the blocking, it will no longer be possible to verify the account again on that smartphone because it is necessary to receive a text message (SMS) or a call to verify the account.
From here, there are two options:
1. The first option is use a new SIM card with the same phone number to activate WhatsApp on the new cell phone. This is the fastest way to disable the app on your lost or stolen device. Only one WhatsApp account can be activated with one phone number and on one device at a time.
2. The other alternative is send an email including the phrase “Phone stolen/lost: Please deactivate my account” in the message and your phone number in full international format.
It is important to keep in mind that, even if the SIM card is blocked and the phone service is suspended, WhatsApp could be used with a Wi-Fi connection if the platform is not contacted to request account deactivation.
“We cannot help you locate your phone. It is also not possible to deactivate your account from another device”, they clarify from the company on its official blog.
If you created a backup in google drive, iCloud either OneDrive before the theft or loss of the mobile, then it will be possible to restore the chat history on the new device.
What happens when an account is deactivated
The account is not completely deleted, and contacts will still be able to view the user’s profile as well as send messages, which will remain pending for a maximum period of 30 days.
If the account is reactivated before it is deleted, then pending messages will be received on the new device. If, on the other hand, the account is not reactivated within that period, then the information will be completely lost.

How to restore a backup to a new cell phone
on Android
If you want to use a locally stored backup, you will need to transfer the files to your phone using a computer, file manager, or SD card.
1. Download an app to manage files.
two. In the application to manage files, go to local storage or “sdcard” folder > WhatsApp > Databases. If the data is not stored on an SD card, other folders named “internal storage” or “main storage” may be displayed.
3. Copy the most recent backup file to the folder Storage Databases location of the new device.
4. Install and open WhatsApp. Then check the number.
5. When indicated, press Restore to recover chats and media files from local backup.
It should be noted that the cell phone stores the backup copies of the last seven days. Local backups are made daily automatically at 2:00 am and saved as a file on the device.
If the data is not in the /sdcard/WhatsApp/ folder, it might be in the folders “internal storage” or “main storage”.

on iOS
1. Sign in with Apple ID which is used to access iCloud Drive.
two. Go to WhatsApp > Settings > Chats > Backup.
2. To restore a backup, you need to use the same phone number that was used to create it. It is not possible to restore the chat history of another WhatsApp account.
3. Because backups are tied to an individual phone number, it’s possible to have backups for multiple WhatsApp accounts stored in the same iCloud account.