How to Find Out the Value of Old Nondenominated US Postage Stamps

I was sorting through some of my late mother's books and papers recently, when I found a dozen or so unused US postage stamps. They were "old" in the sense that the United States Postal Service doesn't print them anymore. But they weren't "old" as in "collectible" or worth anything more than the the denomination printed on them. I decided to put them in my desk and use them. The problem was, some of the postage stamps were unmarked, or "nondenominated", as the USPS refers to them. They had no postage value printed on their face. So how could I tell how much postage each stamp was worth? Read this informative article and learn how to find out the value of old nondenominated US postage stamps and what to do with them.

1. US Postage Stamps Never Expire
I called the local post office for advice. First, the clerk confirmed my belief that US postage stamps never expire. Any stamps you run across- as long as they are uncancelled and unused, of course- can be used for mailing envelopes and packages.

2. Be Careful! Make Sure the Nondenominated Stamps Aren't Valuable!
The stamps I had of my mother's had all been issued in the last ten years. There were some Lady Liberty and Flag First-Class stamps from 2006, some USA First-Class Flag stamps from 2003, and other assorted designs. The clerk at the post office said one has to be careful about postage stamps, especially real old ones. They can be rare, or special in some way, and be worth more than their postage value.

3. Use the USPS' Chart to Find Out the Value of Nondenominated US Postage Stamps
I also found out that post offices have a chart. It has pictures, descriptions, and the denomination of many postage stamps that aren't issued anymore. I think the same chart can be seen at this link: "Quick Service Guide 604a, Basic Standards for All Mailing Services, Nondenominated Postage". This chart starts in 1975 and ends at 2007.

4. Trade-in Old Nondenominated US Postage Stamps for New Postage
As I said, since they never expire, you can use old nondenominated US postage stamps to mail envelopes and packages. But, the clerk at the local post office said you can trade them in for current stamps instead. They will give you equal value. Trading in the postage stamps would make using them easier. As long as the replacement ones have their postage values printed on their faces, that is.

Resources
United States Postal Service
http://pe.usps.gov/text/qsg300/Q604a.htm