Format & Validate Postcode (Zip) on Input
This plugin operates on the input fields of addresses and helps streamline your checkout. For UK and Canada, the format of postcodes is standardised (upper case, separated with a space). For all supported countries, invalid characters are stripped which helps especially with copy/pasted postcodes.
Optionally for the British Isles, the correct country can be set for the Channel Islands and Isle of Man from the postcode if country set to UK. This requires countries GG, IM, JE to be set up (introduced to core in 1.0.8.21).
The plugin does not validate that the value of the postcode corresponds with the rest of the address. If you use a shipping module that obtains quotes from the shipper, it is likely that they also support address lookups - contact me to discuss.
Currently supported countries:
AT, AU, BE, CA, CH, DE, DK, ES, FI, FR, GB, GG, IM, IT, JE, MX, NL, NO, NZ, PT, RO, RS, SE, US
If there is a common input error for your country that the plugin does not correct but could, let me know and I'll add it.