Employees are being urged to check their payslips to ensure they are being paid at least the national minimum wage.
With one month to go before Christmas, those with seasonal jobs in particular are being advised to check they are being paid enough, after October's rise in the minimum wage.
Research from the Department for Business, Innovation and Skills has found that 29% of employees don't check their pay slip.
It also found that 81% of workers struggle to talk to their boss about pay. When asked what would be the most helpful action employers could take, 24% of employees said that clear guidelines on their wages would be helpful.
Employment relations minister Jo Swinson said: "All workers are entitled to be paid the national minimum wage regardless of how many hours they work or how long they have worked for an employer. With minimum wage rates having recently increased, and with employers looking for temporary staff to deal with their Christmas rush, we want to encourage workers to check their payslips.
"Our research shows that 82% of workers who don't think they're getting paid at least the national minimum wage wouldn't approach their boss about it. Any workers looking to make a complaint or for more information should contact the free and confidential pay and work rights helpline."