How is the Royal Mail 13digit reference number calculated?

[Deleted User]

Does anyone know?
Wasn't sure which section of the forum to put this in.

I was wondering what the numbers mean in the 13 digit reference number you get with your royal mail receipt

e.g. mine looks like XBxxxxyyyyzGB

soolin

I thought they were just random. I used to get a pack of orange stickers and although each one in the pack followed the one before, each packet bore no real relation to the previous one.

gollum007

Well, there'll be a checksum ( http://en.wikipedia.org/wiki/Check_digit ) in there, but essentially they'll be random.

-Gollum

custardy

what exactly are you trying to work out?
the 1st 2 letters can identift the products(though this is a bit less reliable as letters become amalgamated.
Eg FD would be Tracked,Zx SD,a K would be 9am SD etc
the last 2 are country code. GB for all of RMs stuff.
the numbers mean nothing

steviebabes

The numbers are sort of sequential, we have full rolls of these and they start ABXXXXX1000GB then jump by 3 or 6 but I've not worked out the sequence. I lost a receipt once but had the 1 before it so kept trying different numbers out until i got one that said delivered.

[Deleted User]

steviebabes wrote: »

The numbers are sort of sequential, we have full rolls of these and they start ABXXXXX1000GB then jump by 3 or 6 but I've not worked out the sequence. I lost a receipt once but had the 1 before it so kept trying different numbers out until i got one that said delivered.

That's what I'm trying to do, but I'm trying to recover the reference number from a package i posted 2/3 weeks ago and lost the receipt for.

theonlywayisup

serenrose wrote: »

That's what I'm trying to do, but I'm trying to recover the reference number from a package i posted 2/3 weeks ago and lost the receipt for.

Unless you have the one before or one after, then you won't be able to guess them.