Instructions
Conduct a "fast and dirty" estimation of the value of your stamps. According to Harry McCulloch, President of the Glen Ellen Philatelic Club, a "fast and dirty" estimation of a stamp collection is twenty cents times the total number of stamps. The twenty cents figure comes from the Scott Catalog, the ultimate reference on stamp value and assumes that the stamps are in "very fine" unused condition. This is likely the lowest value of your British stamp collection, assuming you kept your stamps in a folder, uncreased and dry.
Assess the actual value of your most prized British stamps. Refer to the Scott Catalog for a list of British stamps and their current value. You will need to know the watermark of the stamp and be aware of its current overall condition. Add up the value of those stamps.
Find a number of dealers and receive multiple offers for your stamps before finally selling them. For a list of dealers, review the membership list of the The Association of British Philatelic Societies Ltd. Contact a prospective dealer, and send them an email with a list of your stamps and their respective conditions. Request an offer from the dealers.
Compare the various offers, and sell the stamps to the highest bidder; however, before the final sale, check the offer one more time with the predicted value of your stamps based on the Scott Catalog.