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Canada's official postal code lookup.
Free Lookup for Zip Code, Area code, city, state, time zone, home sales, county and more.
Links to international postal code pages.
"Given a valid U.S. postal address, this server attempts to rewrite the address in the proper format along with the ZIP+4 code."
Links to U.S., Canadian and worldwide telephone directories; also provides links to area code, toll-free and reverse lookup information.
Provides information on how to address a letter or postal item to different countries.
Directory of telephone country codes, prefixes, and numbering systems.
Official United States Postal Service ZIP code lookup.