Dear Sainsburys,

[mcity]

Would it be terribly inconvenient for the self-checkout to calculate the discounts before the user starts to pay, so he or she doesn't end up with an unwanted 93p in change? You already ask people how many bags they used if they swiped a Store Card, why not start calculating then? I don't know if it calculates when one hits "finish and Pay", but it should've worked it out at the bag screen at the very latest.

Srsly
Jonathan