Postmark On Letters

[has]

Can anyone explain what the postmark means on letters that go through the Royal Mail postal process?
I know that the postmark has the date that it was posted and the area it was posted in but what is the (8-digit) number at the bottom of the printed postmark & what does it mean (if anything)?

Thank you...

[Tuvok]

Do you mean on a pre printed envelope? If so its the pre paid licence number.

[Buenchico]

If you're referring to 'machine cancels' (as illustrated at the bottom left of page 5 here: http://www.royalmail.com/sites/default/files/Postmarks_2012.pdf ) then, as far as I'm aware, it's just a sequential number added to each item as it passes through the machines, so that security checks could be carried out if it was alleged that mail was going missing.

[Canary42]

I get "Sorry page not found" on that link

[Canary42]

That message being within the Royal Mail website, I should have added

[bobbinwales]

That's because the link was posted 8 years ago canary