Whatsapp is the world’s most popular messaging service and boasts a user base of well over one billion people.

But a lot of people could soon be stopped from using the app because it’s no longer compatible with a large number of old phone models.

Starting from 1 January 2019 (tomorrow), WhatsApp will no longer allow owners of certain mobiles log on and use the app.

‘This was a tough decision for us to make, but the right one in order to give people better ways to keep in touch with friends, family, and loved ones using WhatsApp,’ it said in a blog post.

“We’ll no longer actively develop for these operating systems, some features might stop functioning at any time. If you currently use an older operating system, we recommend upgrading to a newer version…,” says the chat company on its support page. It suggests the users to upgrade to a newer Android version in case they are using an old one.

The chat company has shared a list of devices that will see the end of the support. Many of the devices in the list have already stopped supporting the app while some are going to lose the support after December 31. Last year, it snapped the support for Windows Phone 8.0, BlackBerry OS and BlackBerry 10 while this year Nokia S40 series phones will stop running WhatsApp after December 31. The company has also confirmed its plans to end drop support for Android Gingerbread and iPhones running iOS 7 or older in 2020.

Meanwhile, here is the list of all OS that have been or will be affected by the WhatsApp’s move. To start with, here are all the operating systems that have already stopped supporting WhatsApp:

— Android versions older than 2.3.3

— Windows Phone 8.0 and older

— iPhone 3GS/iOS 6

— Nokia Symbian S60

— BlackBerry OS and BlackBerry 10

The operating systems that will lose the support after December 31, 2018 are:

— Nokia S40 until December 31, 2018

— Android versions 2.3.7 and older until February 1, 2020

— iOS 7 and older until February 1, 2020

WhatsApp wants you to upgrade to a newer version or to one of these:

— Android running OS 4.0 and above

— iPhone running iOS 8 and above

–Windows Phone 8.1 and above

Last year, WhatsApp dropped its support for Nokia Symbian S60 phones. It then announced plants to do the same for Nokia S40 handsets on December 31, 2018/ Nokia S40 is an operating system which was phased out in 2014.

It was installed in more than 1.5 billion phones. Whatsapp plans to stop support for all iPhones running iOS 7 by February 1, 2020.

This means anyone who owns an iPhone 4 or earlier will have to buy a new phone. Anyone who owns iPhones produced after this will have to update their device if they want to use Whatsapp. A

Also, the app will no longer work on devices running Android 2.3.7 and older after February 1, 2020. Here are all the phones which can no longer use WhatsApp:

Nokia 208
Nokia 301 Single SIM and dual SIM Chat Edition
Nokia 515 Preinstalled WhatsApp New
Nokia Asha 201
Nokia Asha 205 Chat Edition
Nokia Asha 210
Nokia Asha 230 Single SIM and dual SIM models
Nokia Asha 300
Nokia Asha 302
Nokia Asha 303
Nokia Asha 305
Nokia Asha 306
Nokia Asha 308
Nokia Asha 309
Nokia Asha 310
Nokia Asha 311
Nokia Asha 500
Nokia Asha 501
Nokia Asha 502
Nokia Asha 503
Nokia C3-00
Nokia C3-01
Nokia X2-00
Nokia X2-01
Nokia X3-02
Nokia X3-02.5
Nokia 206 Single SIM and dual SIM models.

Source: Metro UK