From today, mobile roaming charges in the European Union have officially been abolished—allowing travellers to make calls and send texts in other countries within the 28-member-state bloc without being saddled with exorbitant bills.

It means that, while the UK is still part of the EU, Brits will also benefit from mobile roaming charges being dropped. Post-Brexit, the government will probably need to strike a deal to try to have a special arrangement in place.

Three boss David Dyson said: "we’re committed to eradicating these excessive charges regardless of Brexit negotiations." It has offered free roaming in Europe for years in an effort to lure people away from rival operators.

Holidaymakers and business folk also need to be minded of the fact that they could still be stung by other mobile charges when travelling to the EU.

Operators lobbied for so-called "fair use" measures to—as the European Commission puts it—"prevent abusive or anomalous usage of the system, such as systematic resale of low-price SIM cards for permanent use in other countries." Brussels' officials say that such policies also help "avoid negative effects on consumers on domestic markets."

There is wriggle room for carriers to bring in small roaming fees, but they would need to seek derogation from the "Roam like at Home" mechanism at a national level.

The commission said: "An exceptional and temporary derogation system for operators to be used only if authorised by the national regulator, under strict circumstances when the end of roaming charges in a specific market could lead to price increases for domestic customers."

Earlier this week, consumer watchdog Which? warned British consumers of the pitfalls of using their mobile devices in the EU. It said:

Even though the UK is still part of the EU, consumers should remember that these regulations only apply to roaming—not to calling EU countries from the UK and prices vary significantly. All mobile providers charge different rates when customers exceed their agreed usage. Although customers are notified when this happens, those who do this while in the EU could face charges ranging from 3p (Three) to 55p (Vodafone) per minute when calling a UK mobile phone. Text and data charges also vary between providers. Vodafone is the only mobile provider that includes popular tourist destination Turkey in their roaming bundle. A phone call from Turkey to the UK on other mobile networks can cost between 69p per minute (Tesco mobile) to £1.65 (TalkTalk).

Customers should check their tariffs and make sure they have the best deal, Which? said, adding that they should always see what else is on offer at the end of their mobile contracts.

Tesco Mobile seized on the anxiety some Brits might have about using their mobiles on holiday to access data, by saying that their "fair use" policy protects the consumer.

The operator said it "wants to ensure that all customers can continue to use their phones abroad with complete peace of mind and this is why Capped contracts are offered as standard. This means that travelling in any country, customers will only ever spend as much as they have set in their safety buffer."