UK Postcode Format Validation

Here is a simple ASP based function that will check a UK postcode to make sure it is in a valid format - it is based on rules from the Government Data Standards Catalogue - The basic rules are...

  • The letters Q, V and X are not used in the first position.
  • The letters I, J and Z are not used in the second position.
  • The only letters to appear in the third position are A, B, C, D, E, F, G, H, J, K, S, T, U and W.
  • The only letters to appear in the fourth position are A, B, E, H, M, N, P, R, V, W, X and Y.
  • The second half of the Postcode is always consistent numeric, alpha, alpha format and the letters C, I, K, M, O and V are never used.

This does only check that the format is valid, it does not know if the actual data is valid, I would be happy to update this script if any public domain reference data could be provided.

Hopefully it will be helpful to somebody!

Download Postcode Format Validation example ยป

Created Wednesday, April 02, 2008, last updated Wednesday, April 02, 2008