Aside from marriage, the avergae British person's longest relationship is likely to be with their bank, with six out of ten (59% or 26.1 million) adults having been with the same bank for 10 years or more, high street lender Alliance & Leicester has revealed.

Time spent banking with the same provider stretches over 10 years or more for 59% of British adults – beating the average amount of time we spend living in a property (seven years), and the average time spent working in any one job (7.5 years). For some, it’s even longer than the average marriage (11 years).

Despite the many current accounts available, a third of Britons (31% or 13.7 million) admit that they have never shopped around for a better deal, and have no idea whether their account is competitive.

A&L advises bank customers to shop around and in a bid to grab a significant slice of those inclined to switch the lender has been operating its Premier Switching Service since October 2005. A&L says that of the thousands of new customers it has won, over three quarters (78%) of 2006 switchers came from its major high street rivals.

Helen Palmer, current accounts manager at Alliance & Leicester, added: Three quarters (73%) of all current account customers have an overdraft facility, with two thirds (66%) making use of it, and two-thirds of them (64%) using it frequently. With people seeming to use their overdraft as part of everyday life, our market-leading interest free overdraft alone should be a compelling reason to declare independence from the big banks and sign up to a better deal.