Halifax said the figures were based on its data combined with government statistics. Previous official estimates have suggested about 700,000 phones are stolen each year.

After Lancaster, the highest number of insurance claims came from the northwest area which includes Chester and the Wirral, and from Coventry, West Midlands. Ipswich in Suffolk had the fewest claims, followed by High Wycombe, in Buckinghamshire, and Oxford. The most expensive phones were stolen in Ilford and Romford, Essex, where the average claim was for 300 pounds.

Vicky Emmott, senior underwriting manager at Halifax Home Insurance, said there had been a rise in "phone-jacking", where thieves target people for their mobiles. "Phones are constantly getting lighter and more compact which makes them easier for opportunistic thieves to swipe," she said in a statement. "Phone users should avoid 'walking and talking' and keep their mobiles out of sight.

The growth in mobile phone use in recent years has fuelled a rise in the number of handsets stolen. Half of all street crime in Britain involves the theft of a mobile, according to statistics published in 2003.

London's police chief Ian Blair said last month that tackling the theft of mobile phones from schoolchildren was one of his top priorities.