HMRC's Card Transactions Programme (formerly credit card sales campaign) is to ask people to declare previously undeclared income from debit and credit card sales.

The campaign is open to all taxpayers and has no closing date. Taxpayers make a disclosure and decide their own penalties.

The advantage of using the campaign is that penalties will be lower than if the information is not volunteered and HMRC catches up with the taxpayers. HMRC will tend to view any undeclared income as being deliberately concealed and so a high rate of penalty will be applied.

Information on credit card sales is pretty difficult to hide given that it is collected by the credit card companies themselves. HMRC can check such sales to the card company records and so it would be a foolish person who did not declare this income.

On penalties: the size of penalty depends on taxpayer behaviour, see Penalties for error.

Links: HMRC Card Transactions Programme