WhatsApp will stop working on millions of phones by January 1

Peer-to-peer messaging app WhatsApp will stop working on millions of phones on January 1, leaving many without access to the popular app.

The change will affect older phones and users will be required to update their software to prevent being hit by the issue.

According to News18, people using older versions of the iOS and Android softwares will be hit.

WhatsApp will reportedly stop working for anyone using an iPhone that hasn't been updated to iOS9 or higher.

For Android users, the app will stop working for those who don't have 4.0.3 Android or newer.

People with iPhone 4 models won't be able to update to more recent software. The same will happen to people with Android devices such as the Motorola Droid Razr and the Samsung Galaxy S2.

To find out what software you are using and whether you need to update before the new year, Apple users should go to their Settings, then go to "General" and "About".

Android users can check their Settings and then select "About Phone".

Will your phone be one of the millions affected? Photo / Getty Images

WhatsApp will warn users who need to update their software in order to continue using the app.

The app is one of the most popular messaging platforms in the world, with more than two billion users.