Employees cost British businesses £10bn a year by keeping in touch with partners during work time, according to research unveiled by Croner.

The survey carried out by YouGov found that 37% of staff had used workplace communications equipment to conduct personal relationships during office hours, with office email systems the most popular means of personal communication.

Office email was cited by 22% of respondents, followed by 21% pointing to the telephone, 18% using personal email accounts on office equipment, 11% liaising with other halves through social networking sites and 6% on company mobile phones.

Working on an estimate that each instance of communication takes five minutes and the average worker receives £17.80 an hour, Croner estimates a company employing 100 people would face paying £35,343 in staff wages for time spent communicating with partners; an average of £353 per person.

Croner is urging employers to introduce clear rules mixed with a bit of common sense when it comes to establishing and enforcing a policy on personal communications in the workplace.

"Most employers will allow staff to make the odd personal call or send a few emails during the day within reason, but if they don't set clear boundaries, the potential for company losses in terms of both time and money is almost limitless," warns HR expert Gillian Dowling.

"Employees should also remember that there may be no such thing as a personal call or email if it is made or sent on equipment owned by their employer," she added.

"Bosses may be monitoring their own systems, and staff could end up facing serious disciplinary action if they're found to be making excessive, illicit or even illegal personal use of communications equipment.

"Clarity is the key to avoiding and managing all these issues before they arise. Staff need to understand what is and isn't seen as acceptable personal use of company equipment, and what the consequences are of stepping outside these boundaries."

The research also found that men were the worst offenders, with 39% admitting to using work equipment to keep in touch with loved ones on a daily basis and 7% of these saying they did so every hour. This compares to figures of 28% and 1% respectively for women.