Originally Posted by
Haleine
Using a coupon that is double digits (e.g. 10 or more) will not be accepted by the cash register at Superstore (Loblaws chain) that is why the cashiers have to either enter it in two single digit denominations (e.g. 2 x $5) or have the supervisor override it. It is a safeguard built into the cash register system so that employees can't favourable treat friends, etc...
Also, at WalMart, the self checkout allows a maximum of 5 coupons per purchase, after that, each additional coupon requires a supervisor override. This safeguard is to avoid allowing self-checkers to enter the same coupons over and over again, maximum outage would be the coupon times 4 (with the original being valid), minimizing the loss to Wal Mart if a self-checker is being dishonest.