Search by location or postcode (zipcode)

Would be great for businesses/comparison websites who have clients throughout the country where they can find locations local to them by the city, or postcode by a search field.

Would need a filtering/method maybe first three letters (letters & digits for postcode/zipcode) to narrow down options, for example if the postcode area code was AB1 and the user user typed in AB1 it would come up with the city/district name etc.