The government has 'named and shamed' 191 companies that have broken national minimum wage laws.
Following investigations by HMRC, the named firms have been fined for owing £2.1 million to over 34,000 workers.
The breaches took place between 2011 and 2018. Named employers have since been made to pay back what they owed to employees and were fined an additional £3.2 million.
According to HMRC, 47% of firms wrongly deducted pay from workers' wages, including for uniform and expenses.
In addition, 30% failed to pay workers for all the time they had worked, such as when they worked overtime, while 19% paid the incorrect apprenticeship rate.
Business Minister Paul Scully said: 'Our minimum wage laws are there to ensure a fair day's work gets a fair day's pay – it is unacceptable for any company to come up short.
'All employers, including those on this list, need to pay workers properly.
'This government will continue to protect workers' rights vigilantly, and employers that short-change workers won't get off lightly.'