So we were very pleased to see we could limit shipping with postcodes. Brilliant. Unfortunately we have discovered It does not seem fit for purpose. In the UK we write postcodes in various ways

Examples

BH217NL

BH21 7NL

Bh217nl

bh217NL

and many more ways

if the customer does these variations it tells them they are not in our shipping area. Just checked our current system ECWID and it works what ever the syntax.