The new Save My Number service, to be introduced on 1 April, lets customers store phone numbers on a secure online site which can be accessed if the handset is lost, stolen or upgraded.

Lloyds TSB says it moved to update its Added Value Accounts range after an online survey found that a third of customers want additional features, with increased phone cover and number back-up the most popular requests.

The online research found that a third of Added Value Accounts customers have either lost their mobile phone or had it stolen. Around 26% of respondents said they had over 100 numbers stored on their handset.

Nearly half of those questioned have no way of knowing the numbers of family, friends and business contacts without their phone, while 53% said gathering all of lost telephone numbers was "the biggest frustration" when their phone went missing.

Ian Larkin, managing director, consumer banking, Lloyds TSB, says: "The new Save My Numbers service is likely to prove a real life-saver for our customers and a valuable addition to their existing package of benefits."

Larkin says mobile phones are increasingly used for receiving bank information and that Lloyds TSB sends more than 500,000 weekly balance updates to customers by text message.

In addition to the back-up service the bank is increasing mobile phone insurance up to £2000, in response to the rising cost of handsets like Blackberries and iPhones. The bank says it replaced or repaired 77,000 mobile phones on behalf of customers in 2007.

The new features are part of a relaunch of Lloyds TSB's Added Value Accounts offering, which sees customers charged a monthly fee in return for a package of insurance-backed services.

Customers signed up to the silver, gold, platinum and premier accounts receive a range of features, including air miles, travel insurance and motor breakdown cover.

Account holders can also sign up for the bank's pre-paid re-loadable Travel Money Card and Money Transfer Card.