Even as a seasoned couponer, I still get stumped at the register. What should be an easy transaction could turn into something you did not anticipate. That’s why it’s a good idea to have your deals written down to include the sales price, the coupons you’ll be using, the rewards you’ll receive, and what your final payout amount will be. Here are four reasons why you should know your final, out-of-pocket amount before you get to checkout!

1. Your coupon may not have rung up

We all listen for the dreaded, loud “ding” at the register indicating that something didn’t scan correctly. However, it might not be your fault. Sometimes the cashier may have two coupons stuck together, you or the cashier may have dropped a coupon, or the register may not have caught the coupon barcode properly. This is why knowing what the final total is before checkout is so important!

2. Your item doesn’t show the right sales price

Whenever I pull anything from its shelf, I make sure to check the sales price. There have been times when I’ve reached checkout and for some reason my item doesn’t ring up on sale. Yes, the computer system should be set to pick up the sales price; however, it’s also your responsibility as the customer to know what the sales price should be. Cashiers are going to be busy ringing up your merchandise, so make it your business to know what the sales price is, and make sure you’re given credit.<

3. You grabbed the wrong product

Been there, done that! Even after checking shelf prices and sales papers, you can still encounter issues. Paying attention to the size or sizes on sale should help immensely. Whenever I’ve encountered issues in the past, it’s been because of a product being misplaced on the shelves. Checking size requirements will help you determine if there are any mistakes at checkout.

4. You don’t get the anticipated reward

Recently, CVS has been having gas card deals with certain purchases and amounts. I took advantage of this the other day and expected a gas card at the end of my transaction—only I didn’t get one. I had the cashier check on the amount I needed to generate the gas card, and I was $1.28 short. It was my mistake, but knowing before I left the store allowed me to get the deal I expected.