I have just implemented shipping by postcode zones. It's a source code update. The problem with using counties is that there is no official list of counties (see other threads in this forum) so it is not 100% reliable.
What I did was firstly add two new AppConfig entries, UsePostcodes and UsePostcodeForShippingZone, in a new group. Then I added validation for all postcode input so that I knew I at least had a valid format. Then I wrote a check in Shipping.ZoneLookup:
Code:
// pbd: start of redirection to postcode lookup.
if (AppLogic.AppConfigBool(ProofByDesignUtils.Constants.AppConfig.UsePostcodeForShippingZone))
{
return ProofByDesignUtils.ZoneLookupPostcode(zip);
}
// pbd: end of redirection to postcode lookup.
I can send you the actual lookup routine if you want to use it.
Our courier, Fastway, was kind enough to send us a full list of their postcode charging areas in relation to our shipping point.
Cheers, Rob