Nationwide, Starling and Monzo gained the most current account customers throughout 2021, according to the latest data from Pay UK.
The biggest losses were seen by HSBC, Tesco Bank and TSB.
Here, Which? reveals the banks and building societies people are moving to - and away from - both between October and December 2021, as well as across the whole of last year.
The most recent data from Pay UK shows the number of full bank account switches between 1 October and 31 December 2021.
The graph below shows how customer numbers changed during this time for a number of banks and building societies - simply click on the tabs to see the gains, losses and overall net gains.
Santander saw the biggest customer gains in this period, with net gains of 36,494 people switching to its current accounts. New customers may have been attracted by the £130 switching incentive it ran towards the end of last year.
Nationwide also proved popular, with net gains of 33,691 at the end of 2021.
Other providers with positive net gains include Starling (10,364), Monzo (3,068) and Triodos Bank (642).
Tesco Bank saw the largest net losses, of -20,278, however, this is because the provider closed its current accounts towards the end of 2021, meaning its customers had to switch elsewhere.
HSBC ended the year with a net loss of -14,875, while Barclays had a net loss of -11,669.
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We've knitted together the Pay UK data from all four quarters of 2021, to give an overall view of which banks and building societies proved to be most and least popular.
The graph below shows overall switching figures for 2021 - each tab shows providers' gains, losses and net gains.
Across the whole of 2021, Nationwide accrued the biggest net gain of 72,594 new current account customers.
Other providers that saw a positive net gain across the whole of 2021 include Virgin Money (19,420), Santander (18,725) and Halifax (10,157).
HSBC saw the biggest net loss in 2021, with a total of -54,140 - that's despite having the biggest gain of 142,995 across the year.
Tesco Bank saw a total net loss of -42,038 last year - but, again, that's mainly because it has now exited the current account market.
Several providers offer switching incentives to encourage new customers to give them a go.
New customers - that is, those who haven't ever previously had a First Direct account, or held an account with HSBC on or after 1 January 2019 - can get £150 for switching to a First Direct 1st account, as long as you pay in at least £1,000 during the first three months.
If you switch to a Halifax Reward or Ultimate Reward current account, you can get £125 in 10 working days. Note that you can't have received a switching incentive from Halifax since April 2020. You'll need to pay in at least £1,500 each month to the Reward account, or else you'll be charged £3 a month to use it. The Ultimate Reward account costs £17 a month. Offer ends on 9 May.
Nationwide is offering a bonus of up to £125 if you switch to its FlexPlus, FlexDirect or FlexAccount. New customers are offered £100, while existing customers can get £125. You'll need to transfer over at least two direct debits to qualify. Note that FlexPlus costs £13 a month.
Instead of a cash bonus, Virgin Money is offering 20,000 Virgin Points when you switch to its Club M or M Plus Account.
To qualify, you must log in to the Virgin Money mobile banking app within 45 days of applying for either of the accounts, move over at least two direct debits when you switch, and save at least £1,000 into the Club M or M Plus saver account, keeping the cash in there until you receive the Virgin Red promo code.
Points can be spent via the Virgin Red app, with offers from participating retailers and charities. For instance, you can buy flights to Paris with Air France from 4,000 points, or a tree top challenge for two with Go Ape with 10,250 points.
While switching offers can be tempting, it's worth making sure a new current account provider offers features that suit you before you make a move.