There are many online resources that offer value estimates of old paper money, including Heritage Auctions, Paper Money Guide, CoinSite and eBay. Professional appraisal by an expert in person is another possible option.
Heritage Auctions lists various U.S. paper currencies that were in circulation from 1840 to 1966, while Paper Money Guide has the most recent examples, listing bills until 2003. CoinSite is very comprehensive, noting the average grade range value, the value of uncirculated currency and the value of uncirculated currency with a star next to the serial number. EBay's "Quick Reference Guide to U.S. Paper Money Value" offers information about the most common types of U.S. notes circulating around the collectible market.
For an appraisal in person, it is often necessary to pay for the service. This fee could range from $200 to $400, according to a 2012 article in Consumer Reports. Contacting the Appraisers Association of America can yield positive results for nearby appraisers. Periodically, free appraisals are offered through Sotheby's and Christie's auction houses. Their websites sometimes advertise "valuation day" or "appraisal day." "Antiques Roadshow," a popular U.S. television program, performs free appraisals, but interested collectors have to buy a ticket to one of its events.