One high street bank lost just over 23,000 customers in the second quarter of this year, according to new figures. More than 265,000 people switched banks between April and June in 2025, with some banks making huge gains, but data from the Current Account Switch Service (CASS) showed Santander lost a net 23,015 customers.

The Spanish bank fared only slightly worse than Barclays, which reportedly lost 18,337 customers, while Halifax was down 14,753. Lloyds Bank and JP Morgan’s Chase followed with 9,406 and 6,976 customer losses respectively. Meanwhile, Nationwide appeared to have a hugely successful quarter, winning five times the number of new customers of any other high street bank, with 54,347 switches.

A Santander spokesperson said: “Our current accounts deliver ongoing value for customers, from cashback on household bills, to access to preferential linked savings accounts paying 6% AER variable. We run a range of promotions from time to time and only recently launched a popular new offer where both new and existing customers can claim a free £100 Amazon gift card by opening one of our current accounts, without even having to switch.”

Alastair Douglas, TotallyMoney CEO, said the figures show Nationwide “remains the dominant player in the switching market”, attributing the huge numbers to its “simple” £200 switch incentive and the Fairer Share scheme, which rewarded more than 4 million members with a £100 loyalty payment.

The Co-operative Bank was the second most popular, with 9,175 switches, according to CASS figures, and Monzo gained 8,246 new customers, which experts attribute to its £50 friend referral scheme. 

Mr Douglas advised: “Remember that loyalty doesn’t pay – but right now, six banks will give you cash for your current account.

“By shopping around, you can find the best offer for your own circumstances, and that could include an interest-free overdraft, high street branches, and improved savings rates.”

He said that the moves were “largely driven by the cash bonus offered by each bank”, but Monzo’s different approach with friend referral bonuses is “clearly working”.

He highlighted six banks that are currently offering bonuses, including Barclays, with a £200 bonus, an Apple TV+ subscription worth £9.99 a month, and Cashback Rewards.

He added: “Just remember that the Blue Rewards account will cost you £5 per month, so it’s best to only switch if you feel you can get the best value from it. And if you earn more than £75k a year, or you have at least £100k in savings with Barclays, they’ll pay you £400 to switch.” 

Lloyds is offering a £200 bonus, however, he poined out the Club Lloyds and Premier Accounts come with a £5 and £15 monthly fee, which could “quickly eat into the bonus”. 

Nationwide will pay a £175 bonus within 10 days, if customers meet all the criteria. There are three accounts to choose from, with the free Flex Direct paying 5% interest on up to £1,500 in savings, and up to £60 cashback in the first year.

First Direct is offering a £175 bonus, and customers will get a £250 interest-free overdraft and access to a savings account paying 7.00% AER.

NatWest is also offering a £175 bonus, and customers will be able to earn up to £5 per month in cashback, but it will cost £2 per month in fees. “Add that to the £175 bonus, and you could make £211 in the first 12 months of opening the account.” 

TSB sits in the middle with a £180 bonus, paid in instalments. Customers get £150 when they switch, and up to £10 per month in cashback for three months. The Spend & Save Plus does come with a £3 fee.

CASS has facilitated 12.1 million switches since its launch 12 years ago.