RegEx for matching UK Postcodes

Question

I\'m after a regex that will validate a full complex UK postcode only within an input string. All of the uncommon postcode forms must be covered as well as the usual. For in

Answer 1

Here's a regex based on the format specified in the documents which are linked to marcj's answer:

/^[A-Z]{1,2}[0-9][0-9A-Z]? ?[0-9][A-Z]{2}$/

The only difference between that and the specs is that the last 2 characters cannot be in [CIKMOV] according to the specs.

Edit: Here's another version which does test for the trailing character limitations.

/^[A-Z]{1,2}[0-9][0-9A-Z]? ?[0-9][A-BD-HJLNP-UW-Z]{2}$/