The Facebook-owned messaging service said that anyone using an unsupported version of WhatsApp would receive an in-app message stating that their account has been "temporarily banned".
If you receive one of these messages, you will have to download the official app to continue using WhatsApp.
The move is an attempt by WhatsApp to stamp out knock-off versions of the app that violate the company's Terms of Service.
SEE ALSO: WhatsApp shares 10 secret tips and tricks you might not know about the app
These include WhatsApp Plus and GB WhatsApp, which are altered versions of WhatsApp that allow users to add different themes or styles.
"WhatsApp doesn't support these third-party apps because we can't validate their security practices," the company said.
If you have been using one of these third-party apps, you can switch over to the official app without losing your chat history.
Head over to WhatsApp's FAQ page for instructions on backing up your chat history before moving to the official WhatsApp app
If you are using the official WhatsApp app and your account is banned, it is probably because you have violated WhatsApp's Terms of Service.
SEE ALSO: Facebook, YouTube, Twitter to face same EU rules on hateful content as broadcasters
You will receive the message: "Your phone number is banned from using WhatsApp. Contact support for help."
If you think your account was banned by mistake, you can email the company and it will look into your case.
The email address is [email protected]
if you are using an Android phone, and if you are on iPhone its [email protected]