Walgreens has a lot of rules and quirks. One rule requires that the number of manufacturer coupons cannot exceed the number of items in the transaction (i.e. to use 10 manufacturer coupons, you must be buying at least 10 items). Manufacturer coupons include Register Rewards but not store coupons. Store coupons are found in the weekly ad, monthly booklet, or W coupons from Sunday inserts.
To make sure checkout is smooth, do a quick count of manufacturer coupons before you go to the register. If you are short of items, add fillers — inexpensive items to up your item count. Great fillers include clearance items, individually wrapped caramels, pencils, gum packets, postcards, a Sunday newspaper, and milk or eggs. Look out for cheap in-ad buys like cans of mandarin oranges or boxes of gelatin.
Also, check out this great idea about using photos as fillers!
To learn more about Walgreens, visit our Walgreens 101 post and print out the Walgreens Coupon Acceptance Policy.