Helpful Advice...

...from someone who works in retail.

Please hand your coupons to the cashier before you swipe your credit card. Once your credit card transaction is approved, we cannot go back and add any discounts. At that point, we have to void your purchase and re-ring it all over again.

For some reason today, I saw an unusual number of people who asked "Can I use this now?" after I handed them a receipt.