Marcus by Goldman Sachs has closed its savings account to new customer after an influx of deposits during the Coronavirus pandemic.
Launched in September 2018 with a market-beating headline interest rate of 1.5%, the online-only instant access account is currently paying out 1.05% after a series of staggered cuts.
But the recent influx of savers has pushed the business close to its regulatory limits, forcing the temporary suspension. British ring-fencing rules currently restrict the sums held on deposit to £25 billion.
The bank says over 500,000 customers have opened accounts and more than £21 billion has been deposited.
A statement posted on the Marcus website says: "In the last couple of months in particular, more people have been opening Online Savings Accounts with us and saving greater amounts of money. As a result, the total amount of deposits we hold has accelerated significantly.
"It’s important that we manage how quickly we grow, at a rate that’s manageable to us. To do this, we’ve decided to temporarily stop accepting applications for our Online Savings Account."