It is no longer news that whatsapp is embarking on an up-grade and it has disclosed that from 31 of December 2016 some phones will not be compatible with whatsapp.
Here is a full report from http://www.express.co.uk official website to that effect

“Some WhatsApp users could be in for
a shock later this year when the hugely-successful messaging app stops
working on their devices.
Earlier this year, the Facebook-owned
firm revealed Nokia S40, Nokia Symbian S60, Android 2.1 and Android 2.2
and Windows Phone 7.1 would no longer be compatible with the app.
That’s not particularly surprisingly. 
But in the same blog post, the cross-platform messenger confirmed it would also be dropping support for all BlackBerry devices.
That includes BlackBerry 10, the Canadian technology firm’s latest mobile operating system. 
In a statement posted on the
company blog, WhatsApp wrote: “As we look ahead to our next seven years,
we want to focus our efforts on the mobile platforms the vast majority
of people use.
“So, the end of 2016, we will be ending support for WhatsApp Messenger on some mobile platforms
“While
these mobile devices have been an important part of our story, they
don’t offer the kind of capabilities we need to expand our app’s
features in the future.
“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.
“If you use
one of these affected mobile devices, we recommend upgrading to a newer
Android, iPhone, or Windows Phone before the end of 2016 to continue
using WhatsApp.”
If you own one of the devices listed above – do not panic.
The
smartphone market is brimming with cutting-edge new devices, and the
next few months will see Samsung and Apple unveil their next-generation
handsets.
So, it’s a great time to upgrade your device. But what should you be looking out for?
Express.co.uk has
rounded up some of the latest smartphones, as well as some of those
that are rumoured to hit UK shelves within the next few months.”

Here is a full  List Of Phones That Will Not Support Whatsapp Anymore From 31st Dec 2016. Check if your phone is a victim.
The affected mobile devices include;
All Blackberry phones including blackberry10 devices
*All Symbian Phones*
Includes; Nokia 500, Nokia E6, Nokia
5228, Nokia 5230, Nokia E63, Nokia 5233, Nokia E66, Nokia
5235, Nokia 5250, Nokia E7, Nokia 5320, Nokia E71, Nokia
5530, Nokia E72, Nokia 5630, Nokia E73, Nokia 5700, Nokia
E75, Nokia 5730, Nokia E90 Communicator, Nokia 5800, Nokia
N76, Nokia 600, Nokia N78, Nokia 603, Nokia N79, Nokia
6110, Nokia N8, Nokia 6120, Nokia N81, Nokia 6121, Nokia
N81 8 GB, Nokia 6124,Nokia N82,Nokia 6210,Nokia N85, Nokia
6220, Nokia N86 8 MP, Nokia 6290, Nokia N95, Nokia 6650
Fold, Nokia N95 8 GB, Nokia 6700, Nokia 6710 Navigator,
Nokia N96, Nokia 6720, Nokia N97, Nokia 6730, Nokia N97
mini, Nokia 6760 Slide, Nokia X5-01, Nokia 6790 Surge, Nokia
X6, Nokia 700, Nokia X7, Nokia 701, Samsung GT-i8510,
Nokia 808 PureView, Samsung GT-l7110, Nokia C5, Samsung
i8910 Omnia HD, Nokia C5-03, Samsung SGH-G810, Nokia
C6, Samsung SGH-iNNN, Nokia C7, Samsung SGH-L870,
Nokia E5, Sony Ericsson Satio, Nokia E51, Sony Ericsson Vivaz,
Nokia E52, Sony Ericsson Vivaz Pro and Nokia E55
*All Nokia S40 Phones*
Includes; Nokia Asha 201, Nokia Asha
300, Nokia Asha 302, okia Asha 303, Nokia Asha 306, Nokia
Asha 311,Nokia C3-00, Nokia C3-01, Nokia X2-00, Nokia
X2-01 and Nokia X3-02
Window phones 7.1
iPhone 3GS/iOS 6
Andriod 2.1 and Andriod 2.2
My advice to you, If you’re planning to buy a new phone for whatsapp purpose only, Please kindly beware of the version to buy as to prevent you from buying unsupported Whatsapp phone.