This is a letter to the Guardian, responding to an earlier Money article about a reader who strung along bank-card scammers by giving them fake details. The letter writer, Gary Calder, offers tips to make such fake details more convincing, suggesting people are keen to have fun turning the tables on fraudsters attempting card scams.

Calder recommends using a genuine issuer identification number (the first six to eight digits of a card) combined with a final check digit that satisfies the Luhn algorithm, so a fabricated card number appears authentic. He also suggests giving scammers amusing postcodes tied to notable addresses, such as those for Downing Street, New Scotland Yard or Windsor Castle, adding a light-hearted twist to countering fraud attempts.