Coupons are always a challenge. Many times they won't scan and they have to manually enter them. Other times the clerk won't even attempt to scan them, they just manually enter them from the start. I have no idea why. We have had many issues with clerks not knowing the coupon policy. Walmart gives you the full value of the coupon, so if you buy something for $2.50 and have a $3.00 coupon, they give you that extra $0.50 that you can use toward other purchases on the same ticket. We have had clerks attempt to adjust the coupon to $2.50 and we had to tell them about their own policy.