One in seven firms in the UK have suffered from staff theft, according to a report by insurance company Eagle Star.
Light-fingered staff are estimated to have cost small businesses more than £112 million in the past three years, helping themselves to everything from petty cash to office equipment.
The amount averages £1,000 a year per firm, affecting the bottom line but also making bosses distrust their employees.
Worst hit are plumbers - one in six have seen equipment or money disappear - followed by convenience stores and newsagents.