Martin Lewis has issued an urgent warning to prevent people missing out on money.
The Money Saving Expert founder said that if you're married or in a civil partnership, you may be entitled to a £1,260 tax break - called the marriage tax allowance. However, it is thought that 2.1million couples miss out on this each year.
Taking to Twitter he advised who would be eligible for the cash. But he urged people to act quickly as they only have six days, until Wednesday, April 5, to sort it.