Recent complaints over onerous bank and credit card charges have prompted several responses. Typical was Tushar Patel, who writes: "Since introducing a debit card/credit card facility about 10 years ago, we have laid down a minimum transaction level of £10 excluding cigarettes, PayPoint and stamps. 

"Failing which, we charge a 75p fee. (For credit cards a 3% charge with a minimum fee of 75p). We have a notice clearly explaining this charge. An average of 50 to 60 customers pay the charge every week, without complaint."

He points out that big multi-national companies like British Airways and Ikea charge for credit card transactions.

My 'northern correspondent' Glyn Reece emailed me a picture of the sign used in Penny's run by his wife in Chester. Their sign says: "PayPoint all payments/top-ups cash only. A debit card may be used 50p surcharge to cover costs."

The sign adds: "The use of debit or credit cards in this store: minimum spend £10. Otherwise a surcharge to cover banking costs: 25p for debit cards; 50p for credit cards."

I'm sure many of you also set a minimum purchase for the acceptance of that dying breed, the written cheque.