Banco Santander SA is racing to retrieve 130 million pounds ($175 million) paid out to thousands of British customers in a Christmas Day slip-up.

Spain’s biggest lender accidentally made a second payment on Dec. 25 to about 75,000 people and firms who had been due for one-off or programed payments from 2,000 businesses with accounts at its U.K. unit.

The blunder has forced Santander to talk to banks whose customers received the money or, in some cases, approach customers directly. The situation was first reported by The Times newspaper.

“We’re sorry that due to a technical issue, some payments from our corporate clients were incorrectly duplicated on the recipients’ accounts,” a spokesperson for Santander said. “None of our clients were at any point left out of pocket as a result and we will be working hard with many banks across the U.K. to recover the duplicated transactions over the coming days.”

The Times said the money went to accounts at banks including Barclays Plc, HSBC Holdings Plc, NatWest, Co-operative Bank and Virgin Money UK Plc.

Some of the banks may be worried that customers may have already spent the funds, the newspaper said. The payments came out of Santander’s own reserves, meaning its own clients weren’t affected.

Santander has 20,000 staff in the U.K., where it runs 450 branches and manages 209 billion pounds of customer loans and 201 billion pounds of client funds.

—By Charles Penty (Bloomberg Mercury)