Q: My mother and I are avid coupon users and are pretty proud of the techniques we use. We have a topic you haven't yet covered in your column: old coupons that have "No Expiration Date" printed on them.

My mother has coupons that date back to the 1980s that state "No Expiration Date." They also do not have a UPC code on them. Are these coupons still good? Will stores honor coupons with no UPC codes?

I know, I know. You are probably wondering why a "couponer extraordinaire" has not used those coupons. My mother always uses coupons with the closest expiration date first, and I guess those coupons from the '80s just haven't been a priority.

With no expiration date, there seems to be no urgency to use them. I call those coupons her coupon children: She just can't get rid of them!

A: I have some bad news for your mom. Her "No Expiration Date" coupons for all practical purposes have expired.

There are several reasons that she'll likely not be able to use them. First, as you pointed out, they do not have a UPC bar code on them. It is unlikely (not impossible, but quite unlikely) that a store will accept them, since they cannot be scanned at the register. Stores rely on the register to scan the coupon's value and match that coupon to the correct item being purchased.

Another reason is that many stores' coupon policies contain a statement similar to this: "Coupons must contain an expiration date and a scannable bar code."

If this terminology is in your store's policy, you have something tangible to show your mom and gently break the news that the coupons are no longer usable.

Whenever I discuss expiration dates, readers inevitably will write to ask why coupons have to expire at all. That's simple: manufacturers want shoppers to purchase the product within a specified time period. An expiration date limits the time in which the manufacturer will have to pay for that coupon's redemption. It also motivates shoppers to buy the product before the coupon expires.

If a product is new to the market, manufacturers typically offer coupons with a shorter expiration date. Those coupons also tend to have a higher-than-average dollar value. Why? They're using the coupon to push the product's price to the "tipping point," where they think shoppers will be willing to suspend their habits and try something new.

Jill Cataldo, is a coupon workshop instructor, writer and mother of three. Learn more about couponing at her website, www.jillcataldo.com.