Money saving guru Martin Lewis says that half a million people across the UK on the minimum wage are being underpaid.
The founder of Money Saving Expert (MSE) has issued a guide to help people check and claw back the money they are owed.
The UK minimum wage increased on April 1, rising 6.6% for those aged 23 and over, from £8.91 per hour to £9.50 hour. And 21-22-year-olds saw their pay rise by 9.8 per cent to £9.18 per hour. All other rates of the National Minimum Wage also increased, as can be seen in the table below.