A good place to value stamps in the UK is at stamp fairs, where stamp dealers value a collection. Alternative places for valuing stamps are specialist stamp auctions or auction houses, which charge a fee. Stanley Gibbons Group offers catalogs for valuing stamps, as well as an online valuation site.
First established in 1856, Stanley Gibbons Group PLC is a British company that is the longest-established rare stamp dealer. Stanley Gibbons continues to produce a number of printed stamp catalogs. Founder Edward Stanley Gibbons was born in the same year that the world's first postage stamp, the Penny Black, was issued.