With more than 700 million monthly users, WhatsApp is now delivering nearly 50% more messages than traditional text messaging.
According to figures from Ofcom, SMS message traffic was at its peak in 2011 and has been declining ever since.
The average number of SMS and MMS sent per person, per month, was recorded at 227 in 2012, which declined to 170 in 2013.
However, SMS is still profitable for mobile operators, generating £40bn during 2013, which is £2bn less than the amount made in 2012.
WhatsApp is handling 30 billion messages every day, which is 10 billion more than the number of SMS sent on a daily basis.
The Telegraph reported Benedict Evans, an analyst for VC firm Andreessen Horowitz, as saying that there were also many other social networks which were taking a bite of traditional mobile revenue, but that there would likely not be one "winner".
Benedict Evans told the Telegraph: "Talking about winners per se seems like it may be the wrong conversation – people use several of these at once for different purposes."
"WhatsApp may win ‘text chat’ but that’s not quite what Instagram is about. After all, your smartphone comes with three social networks out of the box, voice, SMS and email, and you use them all.
"Are you really going to add only one more? So something else may displace WhatsApp in the UK or India for text chat, but it’s more likely that there will be more Snapchats that carve out a slice of time by doing something different."