Urslaan Khan, 41, was baffled when he saw the huge sum in an account – which had previously had just £1 in it.

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He immediately informed Gatehouse Bank.

Urslaan claims he was then told the money was his – leaving him delighted.

But the bank soon realised its error and, a day later, asked Urslaan to return the money.

The admin assistant, from Poplar, East London, paid it all back last Monday.

He said: “I had £1 in my savings account.

“I’d set up a standing order, where £200 is meant to drop from there into my current account.

“But I didn’t have the money in there for that to happen.

“So when it did I went to check my balance – and it said £122k.

“It’s not only the case that they put the money in my account – they even allowed me to transfer it over to my Barclays account.”

Urslaan believes the money was intended for another customer who has at least two accounts with the bank.

He said: “By the looks of it, this person must have two accounts – account A and B.

“The bank should have taken money from A and put it in B. But somewhere along the line it’s ended up in my account – account Z!”

Urslaan sent the money back after speaking to the bank.

He said: “I’d be set up for life if I had kept it.

“But, if I was going to keep the money, I wouldn’t have told anyone!”

And he added: “I took the initiative to make them aware of this.

“I was put on hold three times – only to be assured that there was nothing to worry about.

“And it took them 24 hours to realise their mistake.

“Further to that, I was available to transfer it out my bank to another account.

“I didn’t request the transfer, it just landed in my account.”

Gatehouse Bank said it could not comment on individual customer accounts.

Elsewhere, here are all the banks which are closing in October and disappearing from the high street.

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