Almost a third of staff are never paid overtime, when they work extra hours, a report has found.
But even though most UK employees work in excess of their contracted hours each week, 79 per cent of those questioned said they are happy at work.
The research found 32 per cent of staff claimed they are never paid for working extra hours while 8 per cent said payment is rare.
The Working Family Index, published by Abbey National, also found men are more likely to put in overtime than women.
The majority of employees (64 per cent) said they expect to work late every week with 23 per cent saying they do so each day. Just over three-quarters of men (76 per cent) do regular overtime, compared to 52 per cent of women.
The research, based on responses from 1,000 people, is commissioned by the bank annually to help it shape policies for both staff and customers.
Retail marketing director Gary Hockey-Morley said the bank is committed to helping staff balance work and home life.
He said, “We were amazed to find so many people putting in so many unpaid hours.
“It should not be a rarity for staff to leave at their contracted hour. If anything, modern management should be encouraging employees to undertake their work within contracted hours and leave on time.”