The government has named employers that did not pay some staff the minimum wage.
The official list includes Northern Ireland businesses, horse racing trainers Alan King and Lucinda Russell, and retailer B&Q.
Those named must repay the money owed to employees.
Separately, new figures suggest that wages are trailing inflation.
That is a warning about household budgets.
Prices are increasing at a faster rate than earnings, leaving workers feeling the squeeze.
The government list and the pay data both point to financial strain for workers.
Officials said enforcement action would follow for employers in breach of wage rules.