Workers spend an average of £41 from their desks each week – a total of £3,814 each a year – by shopping online and paying bills during work hours.
Online banking is the most common personal task, with more than a third admitting they regularly check their bank account from their desk.
Other personal tasks regularly carried out during office hours include searching for discount codes and vouchers, buying and selling on websites such as eBay and comparing insurance policy deals.
Booking holidays and keeping up to date with the latest sports news were also popular displacement activities.
Some 38 per cent of workers said they tended to do their own personal jobs during a quiet spell at work.
Another 22 per cent claimed they did not have time to do their own admin in the evenings, while 20 per cent admitted they did it at work because they were bored.
More than one in ten said they did it because colleagues did, which made it okay.
Almost a fifth of workers have missed a deadline or have failed to finish work because they were too busy doing their own personal tasks.
Andy Oldham, managing director of the cashback site Quidco.com, which commissioned the research, said: “Everyone gets distracted at work and it seems many workers are spending a large chunk of their working hours concentrating on personal jobs instead.
“With good internet access on our mobile phones now, shopping and surfing the internet for personal reasons are no longer reserved only for those who work in front of a computer.”
Top 10 personal things done during working hours
1. Online banking
2. Check the weather
3. Check personal emails
4. Read news sites
5. Research holidays
6. Pay bills
7. Browse clothes online
8. Check social networks
9. Call friends
10. Online clothes shopping