Residents and visitors to a Kent village are racking up extra charges when their mobile phones connect to French networks.
When at St Margaret's at Cliffe and St Margaret's Bay near Dover users of mobile devices regularly get "Welcome to France" messages.
Users have been incurring extra costs including data roaming from companies such as Orange F and SFR.
A spokesman from phone company EE said customers should switch off roaming.
The bay is blocked by the white cliffs from receiving UK signals and people in the village sometimes get connected to the French network depending on atmospheric conditions and the weather.
Nigel Wydymus, landlord of the Coastguard pub and restaurant next to the beach, said: "We are a little telecommunications enclave of France here.
"It did not cause a huge amount of trouble for a few years with mobile phones because you got a message saying welcome to France, but since smartphones have come in it's more of a problem.
"Obviously people strolling along the beach in England do not expect to be on a French network and so, unlike when they get off the plane in Spain or elsewhere, they haven't switched off their data roaming and it causes some extra bills."
Costs for making a call on the French network can be up to four times the cost of using a UK network.
The spokesman from EE, which covers the T-Mobile and Orange networks, said: "We always recommend our customers switch off roaming while they are in this little pocket of an area to ensure that they are connecting to the correct network, because we cannot control the networks from the other side of the water."