LONDON, May 15 (Reuters) - Santander told UK customers that all of its banking services were back up and running late on Saturday after technical problems stopped cash withdrawals and online account access for much of the day.

The bank has 14 million customers in Britain and apologised to customers on Twitter for the difficulties.

"All of our banking services are now working as normal," the bank said.

It had earlier advised customers to use other bank's ATMs to withdraw money. (Reporting by Sarah Young, Editing by Mark Potter and Chris Reese)