The BPMA is custodian of two significant collections that together span 400 years of postal heritage: the Royal Mail Archive and the museum collection of the former National Postal Museum. Records in the Royal Mail Archive are Designated as being of outstanding national importance.

Hunting through these collections has uncovered many treasures from our nation's postal history. Treasures of the Archive gives a rare chance to see some of these gems, from a pistol carried by a Mail Coach Guard in the 1800s, to a bag of evidence from the Great Train Robbery of 1963. Many of the objects represent much larger collections which are valuable as a whole.

Objects in the museum collection range from the very large – vehicles and sorting machines – to the very small – handstamps, medals and badges. It includes objects of historical importance, and also more everyday items illuminating the work of a service which has grown to become a part of daily life.

The historic records of Royal Mail Group Limited deal with essential aspects of everyday life beyond the delivery of mail. All aspects of this organisation's unique history, from employment records to stamp artwork, are held within The Royal Mail Archive, one of the oldest business archives in the world.