Customers who joined the network or upgraded after 1 October 2021 will be hit with roaming charges when travelling abroad as of today (23 May).

These users will pay £2 a day when travelling within the EU and £5 a day when travelling outside of the EU.

Pay-as-you-go customers and those who took out a contract with Three before 1 October 2021 are unaffected by this change. Plus, those roaming in the Republic of Ireland are also unaffected.

Three originally announced in September 2021 that it intended to bring back roaming charges, stating at the time: “We know that Go Roam has always been important to our customers and we had hoped to retain this benefit, but unfortunately there are now too many unknowns, which has made it commercially unviable for us to continue. This includes variations to the underlying cost of roaming, meaning we now have no visibility over the maximum amount it will cost us to provide a service for our customers to use their phone while abroad.”

It added that the ‘simple and affordable’ flat charge of £2 or £5 a day means that only those who roam will pay for the service, rather than customers who stay in the UK absorbing the cost.

Ru Bhikha, mobiles expert at Uswitch, said: “It will be a particularly bitter pill to swallow as the network had previously offered some of the most generous roaming allowances, with its Go Roam service covering 71 worldwide destinations, including Australia and the US, as well as Europe.

“If you haven’t upgraded with Three since October 2021 you should be shielded from the new charges, but it is still worth checking your contract. If you are nearing the end of your current deal and want free roaming in Europe without leaving Three you could consider moving to one of its SIM-only pay-as-you-go deals.

“However, a switch to a new provider could mean you can keep roaming for free and save money on your bills. O2 is the last major network not to bring back roaming fees for customers travelling to the EU, but some smaller SIM-only networks also offer inclusive roaming in Europe and could be a good option if you are not venturing too far afield.”

Bhikha added it’s important to check roaming charges for the destination, as well as the provider’s fair use policy which could be lower than the allowance customers are used to.

For those flying to their destination, they’re advised to enable the mobile’s flight mode or to switch off data roaming to avoid racking up charges.

“Use hotel and cafe Wi-Fi connections when on holiday where possible, while ensuring any public access points are safe and secure before logging on,” Bhikha added.

EE, Sky and Vodafone have already brought in roaming charges while Virgin Media O2 have committed to free EU roaming.