Is there any way to check the shipping zip code against a list of zip codes, and if there is a match, create a flag in admin so that we know before hand if the shipment will incur a delivery area surcharge?

I am sure this can be done, but has anyone accomplished this?


problem is I am getting billed $200-$300 extra/month by FedEx because some shipments fall in DAS areas.
If I knew before hand, I could just ship via USPS and save a lot of money.


any ideas? thoughts?