What a first day cover is
An envelope carrying a new stamp, postmarked on the first day it was valid. From the 1960s the Post Office sold special envelopes and postmarks for every issue, and collectors bought them by the thousand. That is the problem: almost every cover from the 1960s onwards was made to be kept, was kept, and exists in quantity.
What the common ones are worth
A box of Royal Mail covers from 1970 to the present sells at auction for roughly the cost of the stamps as postage, less a discount, plus a small amount for the better-known issues. A single cover from that period is worth £1 to £5 to a dealer. Albums of them sell as one lot. Sentimental value is real; market value is not.
The ones worth checking
| Cover | Why it matters |
|---|---|
| Anything before 1953 | Made in small numbers by collectors, not sold by the Post Office |
| 1840 to 1841 Penny Black and 2d Blue covers | The first stamps on their original envelopes, priced by date and condition |
| Wartime and early airmail covers | Postal history collectors buy for the route and the postmark |
| Covers with rare postmarks or cachets | A special handstamp or a scarce sorting office |
| Signed covers | Signed by someone connected to the issue, with a guarantee |
| Covers with errors on the stamps | Missing colours and inverted watermarks are worth more on cover |
How to check a box quickly
Sort by decade. Everything from 1970 onwards goes in one pile and is valued by weight. Anything earlier goes in a second pile for a specialist to look at, photographed front and back. The collection guide explains where to send the photographs.

