TSB has apologised to customers who did not receive payments after a technical issue, and says the problem has now been resolved.
Many customers had taken to social media to say they had not been paid their child benefit on Tuesday, while others said they had not received their salaries.
The bank said all customers who were due money had now received it.
The problems started overnight, with a “small number of customers” affected, it said.
TSB has about five million customers, with two million of those “digitally active” online or through telephone banking.
The bank had earlier told customers that they would “not be out of pocket” for any charges made for late payments.
In a later statement on Tuesday afternoon it said: “We have fixed the issue with BACS payments and have now credited all customer accounts that were due to receive money into them.”
The Downdetector website, which monitors outages of online services, showed hundreds of complaints about TSB on Tuesday morning, with many concerning payments.
One user, Olivia, wrote: “At this point, I’m going to have to borrow money because I’m overdrawn without an overdraft and need to do a food shop.”
Many people were expecting their child benefit, which is due every four weeks on a Monday or Tuesday.
Writing on X, a user called Nicola told HMRC customer service that she had not received her payment.
An HMRC spokesperson said: “Some customers who bank with TSB have not received their Child Benefit today due to issues at the bank. All our systems are working and affected customers should contact TSB.”
The late payment comes after half a million people were left without their child benefit payment in June after a technical issue at HMRC.