From 15 June, O2's Pay Monthly and Business clients will have the capacity to utilize their UK arranges abroad - in 47 European nations - at no additional cost.
The move echoes the rejecting of wandering charges in comparable goals by EE, Three and Vodafone.
It concurs with the approaching annulment of such charges by the European Union on 15 June.
O2 clients will have the capacity to take their UK arrange into some non-EU nations also.
These incorporate Iceland, Switzerland and Monaco.
When going in the Europe Zone outside the UK, O2 clients with the correct arrangements will have the capacity to make calls and send writings to some other nation in the zone at no extra cost.
Getting calls and messages - and utilizing information arranges - is likewise included.
The versatile administrator included that clients would not have to make any move to appreciate the advantages of the change.
While the move would surely profit a few clients, it turned out poorly past what the administrator would need to do under the new EU rules, said Kester Mann, a telecoms examiner at CCS Insight.
Brexit time bomb?
Mr Mann included that UK administrators may think that its hard to reintroduce wandering expenses once the UK left the EU in two years' opportunity.
"I think it would go down, seriously with clients - it would be an extremely intense and maybe rash choice," he told the BBC.
"It would be exceptionally troublesome for them to do that in light of the fact that the UK is such a focused market and we've moved so far from meandering."
Obviously, versatile administrators had taken a "money related hit" from not having the capacity to charge wandering expenses as they had before, Mr Mann said.
Rather, they were progressively attempting to recover that income through different means, he included.
For instance, some had made higher end bundles offering meandering at no additional cost in much more goals abroad.