The government has named companies that underpaid some staff the minimum wage.
The government list includes Northern Ireland businesses, horse racing trainers Alan King and Lucinda Russell, and retailer B&Q.
Those named are expected to repay the money owed to staff.
Separately, official figures suggest that wages are trailing inflation.
That is an economic warning sign.
Prices are increasing at a faster rate than earnings, leaving workers with less spending power.
The government list and the pay data demonstrate financial strain for workers.
Officials said fresh action would follow for employers that underpaid workers.