Millions hit by roaming charges on UK coast & borders
Thu, 9th Jul 2026
More than 5 million people in the UK have had their phones connect to an overseas mobile network while still in the country, according to Uswitch. The comparison site said the switch triggered roaming alerts or charges for about one in 10 adults.
The finding highlights a little-known problem for mobile users in coastal and border areas, where handsets can automatically connect to a stronger foreign signal even if the user has not crossed into another country.
Research cited by Uswitch found that 76% of UK adults either thought this was impossible or did not know it could happen. At the same time, 51% said they were planning a UK staycation, with South West England the most popular destination and South East England second.
That overlap matters because some of the best-known risk areas are on England's south coast and along the Northern Ireland border. Around Dover and Folkestone, phones can pick up French networks while users are still in Kent. In Northern Ireland, devices can connect to networks operating in the Republic of Ireland.
How it happens
Inadvertent roaming happens when a handset is set to automatic network selection and connects to the strongest available signal. In normal use, that setting helps users stay connected. Near coastlines and borders, however, it can cause a phone to lock on to a foreign network instead of a UK one.
Charges depend on the customer's provider and tariff. Uswitch said customers on BT, EE, Vodafone, Three and VOXI may face a daily roaming charge if their phone connects to a foreign network, because EU roaming is not included as standard on those services. Customers on O2, Sky Mobile, Tesco Mobile, iD Mobile, giffgaff, SMARTY, Virgin Media and Talkmobile should not face extra charges from the same type of connection because EU roaming is included in their plans.
The issue is not always limited to a text alert. Among those who said they had received unexpected charges, 39% did not know they could dispute them, while 52% either took no action or paid without questioning the bill.
Rules introduced in 2024 require providers to alert customers when they start roaming. Providers must also take reasonable steps to stop Northern Ireland customers from being billed when their phone connects to an Irish network.
Those protections do not remove the risk of confusion, especially if a connection lasts only briefly or the customer does not realise why an alert has arrived. Refunds are not automatic, and users may need to contact their network to challenge a charge.
Commuter example
Uswitch cited the experience of a commuter in Kent to show how often the problem can occur near the Channel coast.
"Every day on my commute from Deal in Kent, my train runs along the White Cliffs, and my phone often picks up a French mobile signal. I regularly get a text welcoming me to France, even though I'm still in the UK.
"Fortunately, I always keep roaming switched off, so I've never been caught out by unexpected charges. But it shows just how easy it would be for someone to unknowingly connect to an overseas network and end up with a costly roaming bill without ever leaving the country," said Paul Williams.
The survey suggests many travellers may not consider the possibility before setting off on domestic trips. More than a quarter of those planning a staycation said they expected to visit the South West, including Cornwall, Devon and the Dorset coast, while 13% said they were likely to visit South East England, including the Kent coast.
What users can do
Mobile users can reduce the risk of accidental roaming by turning off automatic network selection and manually choosing their UK network before travelling to a high-risk area. They can also disable data roaming and use their provider's app to set a spend cap or block roaming altogether.
Simrat Sharma, Mobile Expert, Uswitch, said: "You don't need to board a plane to face a roaming bill - and with millions of Brits heading to coastal and border regions this summer, many could be in for a nasty surprise.
"When automatic network selection is turned on, your phone connects to whatever signal is strongest - and in coastal areas, that can sometimes mean latching onto a foreign network without ever realising it. Turning off roaming in your settings is the simplest way to avoid being charged.
"Switching it off and manually selecting your UK network before you head to a coastal or border area is the simplest way to stay protected, and it takes two minutes. Most providers also let you set a spend cap or block data roaming altogether through their app - it's worth doing both before you go.
"If you do get caught out, contact your provider straight away - some will waive the charges, but it's not guaranteed, so the sooner you flag it, the better."