Address Correction and ZIP+4 Analysis in Microsoft Excel

Address correction and analysis are important functions for businesses that need to maintain address lists for direct mail campaigns, customer outreach, deliveries, and other purposes. Inaccurate or incomplete address information can unfortunately result in lost contacts, higher mailing costs, and missed service calls, so it is critical to correct address information when necessary and reduce the costs associated with bad data.

Although most address correction software requires exporting data to a custom application, or sending address files to vendors and waiting for the results, Microsoft Excel turns out to be an excellent platform for both storage of address information as well as address correction and analysis.

For instance, it is possible to compare address data to postal service databases by using custom function formulas within Excel. Custom functions are functions used in worksheet formulas that follow a special set of instructions – in this case how to access a database to look up a street name or ZIP code. In the following is an example of a custom function formula:

= LOOKUPZIP(“123 Main Street, Springfield, IL”, “ZIP+4”)

The hypothetical custom function LOOKUPZIP looks for the ZIP+4 code associated with the given street address “123 Main Street, Springfield, IL”, and returns its value to the worksheet. Similarly, an address can be checked against a database like this:

= CORRECTADDRESS(“123 Main Street, Springfield, IL”, “FULLADDRESS”)

Where the custom function CORRECTADDRESS returns the best full address match found in the database, including the ZIP+4 code and standardized address formatting that meets U.S. Postal Service requirements. Following an address correction protocol, misspellings and other errors associated with the original address can also be identified and corrected. Note that in both the formulas shown above, a worksheet cell location (e.g. cell “A1”) can be used in lieu of the given address. This more generalized format allows the formula to be easily copied and applied to a long list of addresses.

Due to the very large size of postal service databases associated with address correction and analysis, it is usually not practical to store them on the user’s PC; they should ideally be stored on a web-accessible server. This does require the user to have access to the internet so the custom functions can access the specified information from the remote database. Also due to the sheer amount of the data involved, data extraction should be done as a bulk data call. Fortunately, Excel is ideally suited for receiving bulk data in the form of arrays. A single formula within an Excel array can do thousands of calculations at once, so using custom functions within arrays significantly speeds up data extraction, especially important when dealing with long lists of addresses.

Excel custom functions have the added bonus of providing a dynamic source of address data and correction. If a change is made in the original address list, the custom function will automatically update the information provided from the database without having to input the formula again. In conventional address correction software, the user needs to import the list into the software and make a new data request, every time the original address list is modified.

Custom functions linked to a remote database can also go beyond address correction to obtain other address-related information, ranging from latitude and longitude coordinates to demographic data. Excel, with its built-in spreadsheet and charting functions, can easily handle the storage and analysis of this type of data.

Microsoft Excel offers a familiar software environment that has proven to be a powerful tool for correction and analysis of address lists. Features like Excel custom function formulas that can access large postal databases, arrays that provide efficient handling of large amounts of data, and dynamic data updating all help make Excel an excellent alternative to conventional address correction software.