Unique ZIP Codes

Zone Improvement Plan (ZIP) is a system of postal codes used by the U.S. They play a crucial role in ensuring that the mail reaches its intended recipient. There are over 41,000 ZIP codes in the country.

Did you know that there is a special ZIP code, designed especially for high-volume mail recipients? These are called unique ZIP codes. These are assigned to government agencies, universities, or buildings that receive large volumes of mail daily.

Since the unique ZIP code is the same for different organizations working in the large building, it might confuse the sender and the mailing system. This is where an address verification system will help. It will verify, validate, and standardize addresses to ensure accuracy.

In this blog we will discuss what is a unique ZIP code, what makes it different from other ZIP codes. We will also talk about the role an address verification system plays in its verification.

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These are the ZIP codes assigned by the US Postal Service to a company, government agency, or establishment that handles large volumes of mail. It can be a medical facility, a university, or any large building with multiple commercial addresses. The standard ZIP codes are assigned to cities and municipalities, based on their geographical location and population density. Unique ZIP codes, on the other hand, are assigned based on the average daily volume of the letter-size mail received. 

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U.S.P.S. simply sends mail with unique ZIP codes to one location. From there on, it is the responsibility of the various organizations, to distribute the mail internally to different departments.  

Since the U.S.P.S. sends the mail in bulk to the institution, they do not maintain a record of the individual deliveries for the unique ZIP codes.  Moreover, while processing unique ZIP codes, the U.S.P.S. Delivery Point Validation (DPV) database sends a yes flag to the delivery indicator, marking the addresses as valid and deliverable.

Institutions can choose whether they want to share their address with U.S.P.S.® or not. In situations where they decide not to save their geographic area in the database, the U.S.P.S. Coding Accuracy Support System (CASS) rule has made it mandatory to assign a default ZIP+4 code to the address during mail processing. This ZIP+4 code is always 0001. When there are actual records with a +4 code of 0001, the mailing system might get confused between a unique ZIP code and a standard one. 

From a sender's point of view, it is understandable how challenging it can be to keep up with the various unique ZIP codes. But if you are unsure or unfamiliar with these codes, your mail might get misdelivered. 

To prevent any confusion or wrong delivery, you must add the correct unique ZIP code in the standard format and verify it. Doing this manually will be time-consuming and prone to error. We recommend investing in credible address verification software and API. By verifying, validating, and standardizing against the local postal addresses, it will ensure address accuracy. 

 Also Read: USPS CASS Certification vs NCOA Certification

There are four different ZIP codes- standard, post office, military, and unique. To understand what makes them different from one another, we need to first understand how ZIP codes work. A ZIP code has the following structure. 

• The first digit represents the region or group of states. The regions are mapped from 0 to 9, moving clockwise across the country. For example, 0 is for the North-east, and 5 is for the West. 
• The second and third digits are used to identify the sectional center facilities(SCF). U.S.A has 900 SCF and each has its distinctive two-digit SCF number. Take, for instance, 55 is for the SCF based in Minneapolis, Minnesota.
• Fourth and fifth digits are unique digits given to the local post office or delivery area.

Hence, the ZIP code 05517 represents region 0 i.e. Northeast, the SCF 55 (Minneapolis), with the local post office or delivery area being 17. 

ZIP Code Extension With ZIP+4 System

After using ZIP codes for a while, U.S.P.S. was looking for an efficient way to deliver mail to specific street addresses. Hence, in 1983 the concept of ZIP+4 code was introduced. This narrows down the location to a specific street, building, or floor, enhancing the accuracy of delivery.  

The original five-digit ZIP code remained unchanged and represents what they did. There was an addition of four more digits. The sixth and seventh digits denote a delivery sector, such as a prominent building or a city block. The eighth and ninth digits of the four-digit code indicate the floor of a building or a specific apartment. You can use U.S.P.S. address verification software to find out the ZIP+4 code.

Let us take the example of the White House to understand ZIP+4 codes. Picked by President George Washington, the White House has the following address: 1600 Pennsylvania Avenue, N.W, Washington, D.C. 20500. You can add different suffixes to reach specific addresses within the White House. Take for, instance, the mail with the code consisting of 0001 as a suffix will reach the President, while 0002 will be sent to the First Lady. 

Any mail sent within the U.S.A. postal zones will have 5-digit ZIP and the ZIP+4 code is optional. However, if you want to make sure that your mail reaches the right address, we strongly recommend adding a ZIP+4 code to your envelope.

Types of ZIP Codes

Standard ZIP Codes

These are some of the most common ZIP codes used in the U.S.A. They are used for general residential and commercial mail delivery. The ZIP code 60606 is a standard ZIP code, denoting various addresses within the city of Chicago, IL.

Post-Office Box-Only ZIP Codes

They are exclusively for P.O. Boxes within a certain postal area. They share the region and SCF codes with the standard ZIP codes, but their post office codes vary. 22313 is an example of a PO Box-only ZIP code. It is assigned to the PO box at the main post office of Alexandria, Virginia. If mails are addressed to the residential or commercial property around it, they will have the standard ZIP code of Alexandria, which is 22314.

You can visit the U.S.P.S. website and find information about the nearest post office and their post box information.

Military ZIP Codes

These are routed to U.S. military personnel stationed abroad or at specific locations. These are characterized by the use of the following address prefixes.

• APO (Army Post Office)
• FPO (Fleet Post Office)
• DPO (Diplomatic Post Office)

The U.S.P.S. has established two-character abbreviations for various military addresses. Take for instance APO AE is used for mail sent to the armed forces in Europe, Africa, Middle Eats, and Canada.

Unique ZIP Codes

As mentioned above, these are assigned to a building or an organization that receives large amounts of mail, daily. While they have the same SCF and postal office codes as standard ZIP codes, their fourth and fifth digit are different. Take for example, the Central Intelligence Agency in Washington, D.C has its unique ZIP code:  20505. However, CIA is located in McLean, Virginia which has standard ZIP codes ranging from 22101–22102.

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Confirm With User

Check whether the user did not enter the unique ZIP code by mistake. You can also contact the operating organization of the ZIP code to confirm the validity.

Use Geographic Information Systems

It is a computer system that captures, stores, checks, and displays data related to the location on the Earth’s surface. Through detailed mapping, GIS can help understand the geographic distribution and coverage of the unique ZIP codes. It can create detailed maps that will display the boundaries and location of areas within a unique ZIP code.

Use Address Verification API

It can check the data against the U.S.P.S. postal database, ensuring that the unique ZIP code is correct. It will speed up the verification and mailing process through automation. This technology is helpful for businesses that incorporate mailers in their marketing strategies and need to make sure the collateral is delivered to the right address.

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General Electric Co, Schenectady

Built by Thomas Edison and now known for its iconic monogram, the General Electric Co. (formerly known as Edison General Electric Company) has a unique ZIP code, 12345. Initially set up in Upstate, when it merged with Thomson-Houston Electric Company, it moved its headquarters to New York City in Schenectady. Instead of sharing the ZIP code with Schenectady's postal service, the headquarters was given its unique ZIP code. 

Dodger Stadium

It is the nation's third-oldest major league baseball stadium, built between 1959 and 1962 by flattening areas around Chavez Ravine. It is also the first sports venue in the U.S. to have its own ZIP code, 90090, which was assigned in June 2009.

Empire State Building

Many skyscrapers in Manhattan's midtown or financial district have been given unique ZIP codes. This art deco skyscraper is one of them, with ZIP code 10118. With many companies operating from the 2.8 million rentable square feet of its commercial floors, it is natural that there will be a huge amount of mail. 

Internal Revenue Service (IRS) Center

It handles a large volume related to tax filing and payments. To streamline the volume of mail they receive, the IRS center in Holstville is assigned a unique ZIP code, 00501.

Walmart, Bentonville, AK

It was founded by Sam Walton in 1962, a few miles outside Bentonville. By the end of the decade, he opened 18 Walmart and 17 Ben Franklin stores.  Now it has become a global company with over 11000 branches in more than 28 countries. It makes sense to assign a unique ZIP code for the headquarters of such a huge organization. In this case, it is 72716.

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Check Whether the ZIP Code is Correct

You don’t have to manually verify each line of the address. By comparing the address to the U.S.P.S. database, Postgrid’s address verification solution ensures that the ZIP code is correct. We will also correct the addresses in real-time, per the national and local records. This will ensure you are sending the mail to the right person/organization.

CASS Certified

We are certified by U.S.P.S. All our addresses are accurate and up-to-date with the latest U.S.P.S. database. We check the validity, correctness, and completeness of the address according to the postal standards. Our address verification tool will reduce the possibility of returns and undelivered mail.

Address Standardization

We ensure that every address is converted into a consistent format according to the postal guidelines. These standardized addresses are then cross-referenced with the U.S.P.S. database, to ensure it is deliverable.

Address Parsing

We break down and structure the address into its consistent components such as street number, street name, city, and state. We structure and standardize the address. Moreover, during parsing, we verify every component of the address against the national record. It will also help detect incorrect or incomplete addresses. Thus,  we ensure that the address you are adding is complete and correct. 

Once integrated with your system, the software and API will automatically fetch the data for parsing, standardization, and address validation within seconds. 

Address Autocomplete

Aside from address verification, PostGrid also offers address autocomplete API which will provide suggestions down to the locality name. Based on the user’s input it will suggest valid options. This feature can prove especially helpful to e-commerce businesses who can incorporate this in their checkout process. 

Geocoding

The geocoding API offers both forward and reverse geocoding, converting addresses into longitudes and latitudes and vice versa. It will pinpoint the exact building and area associated with the unique ZIP code. This address is then standardized against U.S.P.S. CASS, and NCOA databases to ensure accuracy.

We offer geocoding facilities beyond America’s border. You can know the exact location of the address and check the accuracy for more than 245+ countries. 

ZIP Code Lookup

You can use our address verification tool for a full ZIP code lookup. This will verify if the provided ZIP code matches the address saved in the postal database. It will ensure that the address is complete and accurate postal code is used. 

Moreover, ZIP code lookup can be used to determine geographic locations for direct mail marketing. You can create and send highly targeted and relevant mailers such as letters, and postcards, based on demographic and geographic data. This personalization will lead to better engagement with the customers.

Bulk Address Verification

PostGrid allows verification, validation, and standardization of up to one million addresses in one go. All you have to do is upload a CSV or text file with addresses on it, map the column, and address components. Our address verification API will verify it against local and national postal standards and generate a downloadable report for the same.

 Also Read: Benefits of Address Verification Services

Organizations with large-volume mail transitions are assigned unique ZIP codes. However, U.S.P.S. only sends these mails in bulk to addresses with these codes and leaves the responsibility of distribution to the organization.  

Having an address verification system will ensure that you have the correct address, down to ZIP+4 codes. PostGrid’s address verification software and API come with advanced features like parsing, validation, autocomplete, and geocoding will provide verified, accurate, and complete postal addresses.

Want to see our address verification system in action? Request a demo, now.

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