Businesses with undeclared income from debit and credit card sales have been offered the chance to settle their tax affairs on the best terms.
Businesses that make the voluntary disclosure will have four months to pay what they owe from the date they receive an acknowledgement from the Revenue.
HMRC said it has details of all credit and debit card payments to UK businesses. This information is used to identify individuals and businesses that might not have paid what they owe.
People who are found to have undeclared income could face higher penalties or criminal prosecution, HMRC said.