The service, which claims to have over a billion users globally, also said it will not introduce any third-party ads for monetisation.
It further said that while it has asked some of its users to pay a fee for using WhatsApp after their first year, but "as we've grown, we've found that this approach hasn't worked well".
Interestingly, WhatsApp did not charge users for using the service in India, which is one of the biggest markets for the service.
The company, which was acquired by Facebook for $19 billion in 2014, said it was going to experiment with new models to stay ad-free.
"...over the next several weeks, we'll remove fees from the different versions of our app and WhatsApp will no longer charge you for our service," it said.
The company said starting this year it will test tools which will allow its users to communicate with businesses and organisations through its platform.
"That could mean communicating with your bank about whether a recent transaction was fraudulent, or with an airline about a delayed flight.
"We all get these messages elsewhere today - through text messages and phone calls - so we want to test new tools to make this easier to do on WhatsApp, while still giving you an experience without third-party ads and spam," it added.
(With inputs from agencies)