As I just looked this up, and it is not in our coupon policies section, I am adding it. 
Link to the pdf coupon policy.
Basics is this…
Family Dollar Stores, Inc. Coupon Policy
Family Dollar accepts Manufacturer’s and Family Dollar issued coupons (including internet coupons) that meet these requirements:
Coupons must be original (no photocopies)
Coupons must have a scan-able barcode or valid promotion code
Coupons must have a printed expiration date
Coupons can be redeemed only for items sold at Family Dollar, and can be redeemed only for the exact same item (package weight, size, etc.)
Coupons for free items are only accepted if a purchase is required to get one free
Maximum of two coupons per item. One coupon must be a Manufacturer’s Coupon and the second coupon must be a Family Dollar Coupon as long as neither coupon states that it is not valid with other coupons
Family Dollar will NOT accept coupons that:
Are from other retailers
Are expired
Are internet coupons without a scan-able barcode and/or promotion code
Contain the combination of an invalid barcode that won’t scan and promotion code that the register will not accept
Are for “free” items, unless a purchase is required (i.e. Buy one get one
free is acceptable)
Do not have a “remit to:” address on the coupon
In addition: “Cash Back” will not be issued if the value of the coupon is greater than the purchase price of the item.
