Roaming bill shock is a subject widely documented, but you don't expect to rack up the charges in your own home.
That's what's happening to people living in a village near Dover in the UK, who are so close to France their phones often roam onto the networks of Orange France and SFR.
Dover's famous White Cliffs make it difficult for residents and visitors to receive UK signals, and residents say the billing problem is getting worse because smartphones don't always display a welcome message like older handsets, meaning users are unaware they are on the French networks.