Stampless Covers

Stampless covers, also called pre-adhesive mail or pre-stamp mail, are letters that were mailed before postage stamps were issued. The term can also refer to mail sent after the introduction of postage stamps, but unpaid (as was permitted in many countries) or without the payment of the postage charge being indicated by a postage stamp - sometimes the letter was marked paid in handwriting.

This type of mail is usually a letter sheet because the use of envelopes was not popularized until after the introduction of postage stamps, the earliest of which was issued in 1840. Stampless covers include court and government letters and items by the general public before official public mail services were introduced. The mail often bears distinctive town and other marks applied worldwide.

Stampless covers were the norm in the United Kingdom before the Penny Black and two pence Blue stamps (the world's first stamps) were issued in1840. They were also the norm in other countries until those countries starting issuing postage stamps.