Melissa Data's Address Verification Service API Review

Address verification APIs can be difficult to use, but Melissa Data's service is straightforward and easy to use. It offers accurate and complete address data with supplemental data on neighborhoods, weather data, and more. Its user interface is simple to use and the documentation is easier to understand than that of the USPS's. It's also highly reliable, with high uptime.

There are two types of USPS address validation API requests: minimal address validation and complete address validation. The former is the default, while the latter limits the amount of address corrections. The API also doesn't provide a ZIP+4 delivery point, or a two-digit delivery point.

Using the USPS API can be useful for developers who need to check addresses, but it's not ideal for those who need highly reliable, high-volume, or system-critical data. Fortunately, there are other address verification services that developers can use to get a more accurate address.

For example, if an address has multiple addresses, the API will not accept them. If the address has multiple addresses, the API will return an error message with the corresponding address details. Depending on the data in the address, it might include a city, a suite, or a box number. The API also attempts to normalize the address, such as replacing common roadway identifiers with local state codes or reordering the different components of the address. If the address isn't standardized, it won't validate as a delivery point.

The USPS also has a Web Interface that allows developers to validate addresses. While most third-party services offer limited free lookups, the USPS's interface lets users enter a valid address and will inform them if it isn't. Sadly, this feature doesn't support bulk address verification, which is more common in businesses.