Hi,

We have found that, to reproduce accurate addresses, we need to the following structure:

3 address lines of 70 characters.
Post Town (City) 30 Characters
Post Code 7 Characters (8 if also storing the delivery point suffix)

The 'State' equivalent here would be 'County' and required up to 30 characters. It's not actually required by the mail services but a lot of people like to see it on their mail.

The primary source of data for validation, known as PAF (Post Office Address File), is available from Royal Mail. Details (and downloads of related manuals) are at www.royalmail.com/paf/

HTH,
Viv