Chancellor George Osborne has hailed a new guarantee to take the hassle out of switching current accounts as a "powerful" consumer weapon.
From Monday, the new streamlined service will mean that the time it takes to change current accounts will be slashed from up to 30 working days to seven and all outgoing and incoming payments will automatically be redirected to the new provider.
Mr Osborne visited a branch of Metro Bank in Holborn, central London, to speak to customers and bank staff about the switching process.
He said later: "The new seven-day switching service is central to our reforms to build a banking system that works for customers."
The Chancellor continued: "I'm delighted it has now become a powerful weapon for consumers."
There are around 80 million current accounts in the UK and 96% of adults hold at least one account. But Britons typically stick with their current account provider for 17 years, which is longer than the average marriage lasts at 11 and-a-half years, according to recent research from the Payments Council, which is overseeing the new service.
The current low levels of switching are seen as a major barrier to competition between banks, which use the relationship they have with current account customers to sell them other products.
The Payments Council found that two-fifths (43%) of people would consider switching their current account, although just one in 17 (6%) have actually done so in the last two years , rising to one in 10 (10%) 25-34-year-olds.
Meanwhile, more than one third (37%) of people have switched their car insurance provider in the same period.
Some 33 bank and building society brands, accounting for almost the whole market, have signed up to the agreement, which will see payments accidentally made to the old account automatically redirected for 13 months after the switch.
Details of the new guarantee will be displayed in bank branches and on websites and c ustomers will be refunded interest and charges if anything goes wrong.
There have already been signs of providers ramping up competition in recent weeks. First Direct, which often comes out top in customer service studies, has upped a cash incentive for people to switch to it to £125.
Halifax is also offering £100 for customers to switch, while NatWest and RBS recently launched a new debit card-linked loyalty scheme called "cashback plus". Customers who register for the NatWest/RBS scheme get back at least 1% of their spending at selected retailers, which can be banked or exchanged for gift cards.
Market research firm Consumer Intelligence said its analysis suggests that the Halifax Reward account and the Santander's 123 account stand out as giving particularly good returns for customers who tend to remain in credit.
The Reward account pays £5 a month to customers who put £750 a month into their account and remain in credit throughout the previous month, while the 123 account offers cashback on household bills paid through the account as well as in-credit interest.
Rachel Springall, spokeswoman for financial information website Moneyfacts, said people should look beyond initial perks when deciding whether to switch.
She said: "Making a decision on which current account to choose should be based on your spending habits and not just for enticing incentives.
"Upfront cashback or interest-free deals are great but if you are regularly overdrawn you should weigh up overdraft charges and check whether the new lender will match your current limit."