U.S. ZIP +4 Database FAQs
ZIP +4 Database Frequently Asked Questions
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ZIP+4 Database FAQs
Why trust our ZIP+4 Database?
A lot of companies make claims that they are the best but we truly feel no other ZIP Code provider provides nearly the quality of data and support as we do. We've been in operation since 2003 and have an extensive customer list of fortune 500 companies, individuals and small businesses. We also answer our phones. Seriously, we do not hide. Call us at 1-800-425-1169. ZIP-Codes.com was the first to offer an unconditional money back guarantee because we know our ZIP Code Database quality is superior. We are not just licensees of the USPS, we work directly with them and they license data back from us. We also work directly with other data vendors such as Pitney Bowes. Quality and service are our #1 priorities. But do not just trust us. See why you should choose us.
Are there parts to a ZIP Code?
Yes, a full ZIP+4 is actually comprised of 5 parts. 12345-6789 for instance may be grouped as   [ - ]  .
Why do ZIP+4 records come in low/high ranges instead of individually?
For most addresses, a single ZIP+4 is the norm. Just 1 ZIP+4 will cover several houses on a block or side of the street. However, large businesses or those receiving a large volume of mail may be given a range of ZIP+4 codes so that they can route mail to specific departments. A range of ZIP+4 codes may also be assigned to a corresponding range of PO Boxes (PO Box 1004 would have ZIP+4 1004), or a single PO Box could have a full range of ZIP+4 codes (PO Box 1004 would have ZIP+4 1000 through 1100).
Because the USPS allows some instances of ZIP+4 ranges, the requirement to display the data in ranges applies to even singular ZIP+4 codes.
Do you have every ZIP+4 in the U.S. listed separately?
Unfortunately, due to the reasons listed above, no. The ZIP+4 data is only available in ranges.
What does ND as the last two characters in a ZIP+4 mean?
ND as the last two characters in a ZIP+4 mean “Non Deliverable”. It simply means that the USPS has this in their system, but does not actively deliver the mail to that address. USPS documentation has this to say about non-deliverable addresses: “Non-deliverable areas are areas to which the USPS does not deliver mail, such as vacant lots and land that borders railroad tracks. Mailers should not match an address identified as a non-delivery area.”
How do you match data from 5-digit database to the ZIP+4 database?
The ZIP+4 database is very large and is missing certain pieces of information such as City. City information can be retrieved from the included 5-digit ZIP Code database.
Most people match ZIP+4 to ZIP Code in the 5 digit ZIP Code Database using just the ZIP Code. While this method works, a more precise method of matching is using the Preferred Last Line City State key from the ZIP+4 database and matching this to the City State Key in the 5 digit ZIP Code Database. This will provide the city and state names which are available for this ZIP+4 record. From there, please use the MailingName field to determine if a City Alias is valid for mailing purposes or not.
Urbanization names only exist for records in Puerto Rico. For Puerto Rico ZIP+4 records only, you can obtain the Urbanization City State Key and match this to the City State Key in the 5 digit ZIP Code database. In the matching 5 digit ZIP Code database record, the City Name field will contain the urbanization name. The same process is used to obtain the municipality name.
The city name in the 5 digit ZIP Code Database can contain many types of names: preferred last-line, urbanization, municipality, and other names by which a given 5-digit ZIP Code is known.
Do you have any other formats for the data?
Unfortunately, no. CSV is the most concise and versatile format for transferring the ZIP+4 data from system to system. It is the only data format we provide this information in.
What is from/to latitude and longitude
ZIP+4 records, for the most part, represents a number of houses, apartments, or businesses along a street. They do not represent singular points. In an attempt to provide more useful information regarding location, a starting point (From Latitude and From Longitude) indicate where a ZIP+4 record begins while the ending point (To Latitude and To Longitude) indicates where it begins. All areas between those two points can be thought of as being part of that ZIP+4.
Unfortunately, not all ZIP+4 Codes are straight lines. Many areas curve, bend, and follow streets that are not in a straight line, so some interpretation and understanding of what is physically in between those two points must be taken into account.
Q. What methods of payment do you accept?
A. We accept Visa, Mastercard, American Express, and PayPal for immediate download. You can also place your order choosing Mail In Check or Purchase Order but you will be unable to download the database until your payment is received.
Q. Do you accept purchase orders?
A. Yes, we can accept purchase orders. Simply go through the order process as normal. When you come to the payment screen, choose Purchase Order as the payment type and complete your order. You can then print out a purchase order and mail in the payment. Once payment is received, access to download the database will be turned on.
Q. What format does the database come in?
A.Our US ZIP +4 Database is provided in ASCII Comma Delimited [CSV].
Q. How do I get the monthly database updates?
A. When you purchase, you setup a username and password. Each month, we will notify you via email that an updated database is available. Visit our site and login using your username and password. The updated databases will be available for download in any format we provide as well as a transactional log file with just the changes only.
Q. Will a CD be mailed to me? How do I get the database?
A. Yes, our US ZIP +4 Database is mailed to you on CD. Once your order is completed, you will also be able to download immediately. All monthly updates are also provided for online download. This ensures fastest delivery as the database is updated each month.
Q. What happens after my 1 year subscription?
A. When your ZIP+4 Database subscription is expiring, we will notify you by email 30, 10, and 1 day in advance. You can choose to renew at the current rate, or let your subscription expire. You can continue to use the database after your subscription has expired, but if you don't renew, you won't continue to get monthly updates.
Q. How much does it cost to renew?
A. Currently, renewal prices are the same as the original purchase price.
Q. Do you include ZIP Codes for the entire United States?
A. Yes. ZIP Code data is provided for all 50 U.S. States, Washington DC, Puerto Rico, Virgin Islands, Guam, and APO/FPO Military ZIP Codes.
Q. How often do you update the database?
A. Our ZIP Code Database is updated every month.
Q. How current is the data?
A. Our ZIP Code Database is updated every month. the data is current as of December, 2023
Q. What are the sources of the data?
A. Our ZIP+4 Database is licensed and compiled from various sources. Postal and Delivery data comes from the USPS, Demographic data from the US Census, Statistical Areas from the OMB (Office of Management & Budget), private data sources, and some are computed by Zip-Codes.com.
Q. How accurate is the data?
A. Accurate data is critical to the success of your business and ours. Zip-Codes.com implements a very rigorous set of data integrity checks to ensure our database is as accurate as possible. In the unlikely event that a portion of data is confirmed as innaccurate, we will correct it within 2 business days.
Q. Do you have any other countries besides the U.S.?
Q. How long does it take to get the data?
A. Instantly. As soon as your order is confirmed and payment is received, you can download the database.
Q. Can I automate the database delivery?
A. Yes! Please email us requesting an FTP Account be setup for you to use in automating your processes. Please include your username or order number for reference. We will have it up and running within 1 hour.
Q. Do ZIP Codes change often?
A. ZIP code data changes frequently. Every year there are thousands of changes to the USPS ZIP Code records. Cities are added and removed. ZIP codes are created or discontinued. Corrections are made. Boundaries change. Streets are added and street names change. Within a short time period, the database will be outdated if you do not download it every month.
Q. Do you support Military APO/FPO/DPO ZIP Codes??
A. Yes! Overseas military post offices operated or supported by the Army or Air Force use the city abbreviation APO [Army Post Office / Air (Force) Post Office], while overseas military post offices operated or supported by the Navy, Marine Corps or U.S. Coast Guard use the city abbreviation FPO (Fleet Post Office). Recently, the Department of State has begun establishing a semi-independent overseas postal system. Their city abbreviation is DPO. As of March 2009, less than 10 U.S. Embassy locations are known as DPOs. The other approximately 90 overseas U.S. embassy post offices fall under the management oversight of the military services and so are known as either as APOs or FPOs. Three quasi-state codes have been assigned depending on the (approximate) geographic location of the military mail recipient and also the carrier route to be taken. They are:
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Q. Do you have DMA information?
A. No, Nielsen is the provider of that data and they do not allow others to redistribute it. If you need it, you need to go directly to them to get it at Nielsen.com
Q. How long have you been in business?
A. We have been selling our databases online since 2003 and have become the most trusted source of ZIP code data.
Q. What separates you from your competitors?
A. What separates us from our competitors is our level of customer service. We are here every day and we answer the phones during business hours. If you have a question or problem, we are here to help you. Additionally, we provide the most comprehensive database at the most competitive price. Our competition doesn't even come close. Try calling them! Also, our rigorous data integrity checks make our data the most accurate you can purchase.
Portions of data provided by and © United States Postal Service 2023. Zip-Codes.com is a non-exclusive licensee of the United States Postal Service.