Users of 43 different models of smartphones will soon be unable to use the popular instant messaging app WhatsApp.
On November 1, the Facebook-owned platform will stop working on phones that run on systems older than Android OS 4.1, Apple's iOS 10 and KaiOS 2.5.1, according to its FAQ section.
All of these phones will not receive support from WhatsApp and will be incompatible with the app.
If this includes your device, you'll need to upgrade to a newer model of phone that has an operating system the company supports – or use a different messaging service altogether.
If you choose the former, then here's what you can do with your old mobile phone once you've got your new device.
However, the company has also introduced a new feature – "one of the most requested features", according to a blog post – to allow users to migrate their chats when switching from iOS to Samsung Android devices.
Before this, iOS chat histories would be stored in iCloud, while Android histories went to Google Drive, making it nearly impossible to transfer chats between phones that use different operating systems. Users would be advised to instead email their chat histories to themselves.
The new feature encompasses voice messages, photos and videos, but not call history or display name.
"To start, this feature is available on any Samsung device running Android 10 or higher, and will be available on more Android devices soon," said WhatsApp.
In a tweet, WhatsApp announced the update was available as of September 3, and that it would also be available "soon across all devices".
The migration will also need to be completed during the initial set-up of new phones, as the WhatsApp instructions read: "Your new Android device must be factory new or reset to factory settings." Users would alternatively need to do a factory reset of a device if already using it. Find out how to do it here.
"This is just a start," said WhatsApp in the blog post. "We look forward to making this option available for more people to switch between platforms of their choice and securely take their chats with them."
Which smartphones will no longer be able to use WhatsApp fom November 1?
The first generation iPhone SE, 6s and 6s Plus.
The Samsung Galaxy Trend Lite, Galaxy Trend II, Galaxy S2, Galaxy S3 mini, Galaxy Xcover 2, Galaxy Core and Galaxy Ace 2.
The LG Lucid 2, Optimus F7, Optimus F5, Optimus L3 II Dual, Optimus F5, Optimus L5, Optimus L5 II, Optimus L5 Dual, Optimus L3 II, Optimus L7, Optimus L7 II Dual, Optimus L7 II, Optimus F6, Enact, Optimus L4 II Dual, Optimus F3, Optimus L4 II, Optimus L2 II, Optimus Nitro HD and 4X HD, and Optimus F3Q.
The ZTE Grand S Flex, ZTE V956, Grand X Quad V987 and Grand Memo.
The Huawei Ascend G740, Ascend Mate, Ascend D Quad XL, Ascend D1 Quad XL, Ascend P1 S and Ascend D2.
The Sony Xperia Miro, Sony Xperia Neo L and Xperia Arc S.
The Alcatel One Touch Evo 7, Archos 53 Platinum, HTC Desire 500, Caterpillar Cat B15, Wiko Cink Five, Wiko Darknight, Lenovo A820, UMi X2, Faea F1 and THL W8.