Not all Falls Church mailing addresses are located within city limits--some are in Fairfax County (like Merrifield, Seven Corners, and Bailey's Crossroads). To determine if an address is within the City, please use the following tools.
United States Postal Service Database Go to this website, enter your address, and click "Find." When the results are provided click to expand "Show Mailing Industry Details." This option will show your "County."