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

^([A-PR-UWYZ0-9][A-HK-Y0-9][AEHMNPRTVXY0-9]?[ABEHMNPRVWXY0-9]? {1,2}[0-9][ABD-HJLN-UW-Z]{2}|GIR 0AA)$

Regular expression to match valid UK postcodes. In the UK postal system not all letters are used in all positions (the same with vehicle registration plates) and there are various rules to govern this. This regex takes into account those rules. Details of the rules: First half of postcode Valid formats [A-Z][A-Z][0-9][A-Z] [A-Z][A-Z][0-9][0-9] [A-Z][0-9][0-9] [A-Z][A-Z][0-9] [A-Z][A-Z][A-Z] [A-Z][0-9][A-Z] [A-Z][0-9] Exceptions Position - First. Contraint - QVX not used Position - Second. Contraint - IJZ not used except in GIR 0AA Position - Third. Constraint - AEHMNPRTVXY only used Position - Forth. Contraint - ABEHMNPRVWXY Second half of postcode Valid formats [0-9][A-Z][A-Z] Exceptions Position - Second and Third. Contraint - CIKMOV not used

http://regexlib.com/REDetails.aspx?regexp_id=260