Proactive Investors - Mobile phone companies will have to alert travellers to the costs of calls made when outside the UK under proposals unveiled by Ofcom.
The regulator said one in five people are unaware of the roaming charges that apply when making mobile phone calls or using data from outside of the UK.
Ofcom said it wants people to be alerted about potential fees and also what actions they can take to limit the costs of using their phones overseas.
Most networks charge people approximately £2 a day to use their phone abroad, said Ofcom, with the total cost running to more than half a billion pounds yearly.
A final decision will be made next year with mobile providers given six months to implement the new rules.
Roaming charges were banned in the European Union in 2017 but Brexit allowed UK providers to reintroduce them in 2021.
Three, EE and Vodafone (LON:VOD) all reintroduced roaming fees for customers travelling to the EU in 2022, while O2 says customers can use up to 25GB of data in a month before being charged.
Ofcom also said wants customers to receive an alert if they are at risk of when "inadvertent roaming" when their phone might connect to a network in a different country, such as between Northern Ireland and the Republic or even the parts of the Kent coast closest to France.
Specific tariffs, or even forcing networks to "treat mobile usage in Ireland the same as being in the UK". Are under consideration said Cristina Luna-Esteban, Ofcom director of telecoms consumer protection.
"These alerts would mean whichever mobile provider you're with, you won't be left in the dark about roaming charges and actions you can take to manage your spending."