How Does Address Validation Work?

How Does Address Verification Work Even among professionals, the exact knowledge of how postal address validation works is not always shared by everyone alike. The validation systems, in the form of more or less advanced computer software, each have different technologies and functionalities, so the idea users receive about the real validation mechanism of postal addresses can vary greatly, not only based on the program used (and more specifically on the version of the program used), but also according to the reference language and the target country. We at Address 4 have the great advantage of knowing every aspect of the subject (especially on the development front), and we can talk from a more advanced perspective than any other end user.

In light of the above, we want to offer readers of our site the chance to learn more about how last generation validation software of postal systems works, backed by decades of experience gained by our company in this sector. We will therefore see the many factors that come into play when an address is assigned to computer programs dedicated to validation, and what results can be obtained with these tools in the main configurations of use available (real time, batch, plugin, API). We begin by outlining the major services related to the normalisation of postal addresses in relation to the resources available with the Address 4 software.

The first job option that we mention is online address standardisation, a service that allows you to correct and verify any postal address by entering the data in a template or form within a specific page. In this case, data processing takes place remotely, 24 hours a day, 7 days a week. The most obvious advantages are practicality and calculation speed, useful factors when you need to obtain a validated address immediately.

Address autocompletion is preferred in particular by those responsible for data entry activities. In this case the software is accessible in the back office in the management system or in the company application, or it is integrated into the front end inside ecommerce and portals to facilitate the entry of an address by the user (typically during a purchase, but not only). In both cases the goal is to guarantee secure data entry, avoiding any errors in filling in the fields.

Postal address validation can also work in massive form (batch), i.e. for entire databases and not for single addresses entered one at a time. In this case, the operator can send a database with hundreds of thousands of addresses, setting – as in the other cases – the desired parameters (output language, destination country, etc.). The result is an equivalent standardised and ready to use address file in the most varied business areas.

Another service attributable to postal address standardisation is the formatting of the addresses themselves. Formatting is an advanced process whose purpose is to return one or more addresses in the format appropriate to the dispatch. In fact, each country adopts its own postal system and each postal system implies a precise address format. With formatting, data is sorted and transcribed according to the scheme provided by the designated postal system.


What we have seen so far are services for validating the more recurrent addresses. One or the other type of processing allows managing different data in numerical and qualitative terms, preferring a certain result according to the needs at the time. At the moment in which we pass from theory to practice, we must however fully understand another aspect of validation: how and where does the processing of addresses take place? On your PC? Online only? Via smartphone app? To answer we must proceed further and deepen our overview. First of all, each validation service takes the form of a series of alternative virtual tools and environments, so as to ensure maximum flexibility to the user, also based on his or her level of experience. The most frequent options include:

Address validation in real time

One of the most requested validation options is undoubtedly the real time address validation. With this we refer to the validation versions that occur simultaneously with data entry, for example when the customer fills in the fields of an ecommerce order, but also online using cutting-edge software such as Address 4. The real time resets the user’s margin of error, speeds up data entry and improves the experience of using the store or program.

Address validation with API

If real time works only online remotely, API is a processing method integrated into the website, platform or CRM, even for offline use and for batch processing of large volumes of data. API is nothing more than the set of procedures aimed at carrying out the postal address validation according to the set parameters. This is a very popular option for those who need direct control over the validation features, at a level that is certainly greater than what is possible with real time validation.

Address validation with plug-in

In addition to its own application, Address 4 can be integrated into third-party applications and CMS, from Magento to WordPress, from WooCommerce to Hubspot… Here, too, the most obvious advantage is having direct control over address validation activities, and not forgetting the practicality of a system capable of working online and offline much faster and with results always up to expectations. The range of reproducible plug-ins is almost infinite and translates into a perfect match between the customer’s needs and the validation performance.


So far we have seen how postal address validation in its numerous operational declinations works. We also mentioned another important aspect, namely the diversity of validations related to the diversity of countries and geographical areas. It is not said that the launch of a validation returns identical outcomes in all the countries considered. In this regard, we at Address 4 have created an interactive map with guaranteed coverage in over 250 countries around the world. By clicking on each state, you can see the type of coverage, whether generic (locally) or specific (street), also knowing the available functions between geocoding, deduplication, address validation, etc. Finally the characters of the postal format are shown, including native, transliterated or Latin. If you want immediate feedback on the functioning of postal address validation, please try our free online demo. By entering your data you will be able to get free trial credits, access to advanced features and update the address database automatically without needing to install anything. In addition, you will receive the free ebook with the data quality secrets. Take advantage of it today without any commitment.