3 has removed the data cap on its 'The One Plan', which is aimed at smartphone users.
The mobile network said this move means Brits really do have access to 'unlimited' data when using their handset.
3 said the change is aimed at giving customers peace of mind when it comes to data , "so they can surf, email, update, watch, listen or play freely on their smartphone - making the most of all it can do". The firm reasoned that many smartphone users don't use the handset's full functions for fear of unexpected charges.
"Every day, thousands of customers buy a smartphone on a two-year contract. The trends clearly show usage grows over time. With its all-you-can-eat data, The One Plan will still fit your needs, no matter how much data you use," said 3's sales and marketing director, Marc Allera.
"We expect to see more people using mobiles than PCs to access the internet by 2015. All-you-can-eat data is designed to remove the possibility of bill shock when you use data, so you can use your smartphone to do everything it was designed for without the worry of cost."
Mobile networks began introducing data caps on tariffs earlier this year following fears that too much data usage would put the networks under strain. However, while operators including Orange and O2 enforce data caps of 500MB per month, 3's The One Plan had been capped at 1GB per month.
However, Ben Woods from CSS Insight warned the mobile network it could be putting itself under strain.
"This is great news for prolific mobile data users, but 3 will need to be careful it does not end up attracting all the extreme users who have proved a real headache to rival networks with their excessive data usage," he told the BBC.
The One plan was first launched in July this year, and is priced at £25 per month and comes with 2,000 cross network minutes, 5,000 minutes to other 3 numbers and 5,000 texts as well as the unlimited data.