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Developer Notes

Bryan Wats
Automated connection with PostNL in a snap.

Claris FileMaker

Since the advent of the Internet and mobile smart phones, people have started to email more and more when in contact with each other: letters have made way for emails, contracts can be signed digitally (see my other blog post about this) and SMS has made way for apps. Customer contact has never been so quick and efficient.

However, there are situations imaginable in which an e-mail address or (mobile) telephone number is not sufficient. What if your company delivers products or services to your home? At that point a correct address is important. This is where the specialists of Lesterius can help.

Together with you, our client, Lesterius builds a customized solution based on the Claris FileMaker platform. In this solution all data that is applicable at that moment will appear on your desktop or tablet, such as a customer address with postcode.

FileMaker integrates

Contrary to popular belief, FileMaker no longer stands alone. Your solution can link to external data sources and retrieve data. The possibilities are endless, addresses are just one example. These can then be nicely displayed within FileMaker, such as in a Google Maps window or even better: start up your favourite Maps app and let it guide your ride!

The computer does the work

Wherever data is entered, mistakes can be made. These can be overcome with validation, but wouldn’t it be nicer if the computer itself did as much of the work for you as possible? Automation allows us to take over part of the input process. This involves making a connection to PostNL, the authority in the Netherlands, which returns the complete address based on what has already been entered. In principle, postcode house number is sufficient.1

In the Netherlands, PostNL has done a good job with the classification of postal codes. Each postcode has a unique street name. Therefore, an address consisting of at least a postcode and house number is sufficient for delivery. This is different in other countries; postcode areas are larger.

Serving your customers

The advantage of filling in the form is not only for you (the administrator), but also for your customers! They have less work on your web page; after all, some street names are quite long. Moreover, you are assured of a correct address. PostNL offers various services, depending on the size of the search area and the data required.

What to choose?

PostNL offers the following API services:

  • Address check Benelux
  • National address check
  • Address Check International
  • Geo address check National

The product “Addresscheck Basic National” will be discontinued in the near future.

Which service is most suitable for your situation, will become clear in the preliminary process with Lesterius. For example, it may be useful to get coordinates for a precise location on a map. As an example I would like to mention Riet Beheer; they provide maintenance of thatched roofs. This company is actively seeking opportunities to support their primary business operations with the possibilities of modern technology. For example, they not only have drones in operation to track down problem areas and point them out to the customer, but also their administration in FileMaker. Typically, work is carried out on farms in the more remote areas of the Netherlands. The customer does not always provide complete address details required for invoicing. Entering the postcode is experienced as tedious. Through a link to PostNL, data are supplemented and, if necessary, corrected in the format that PostNL likes: “1234 AB GEMEENTE”. (Note: a space in the postcode for readability and then two spaces between postcode and city). In addition, PostNL returns detailed coordinates that can be used to locate it in Google Maps and then mark it.

How does it work?

You decide on an API subscription with PostNL, we can arrange this for you. Lesterius is not tied to PostNL, the most suitable solution from any third party will be discussed with you. We put the necessary code in the solution. This can be a button that sends the address request, but also more automated. It may be that PostNL cannot find a suitable address, in which case the result differs too much from the address details entered. How certain the result is, is indicated in a percentage. Based on this, further action can be taken, for example a Google search. A 100% result is of course entered immediately. If a “loose” search is carried out in Belgium, there is a good chance that several results will be found. An appropriate interface can be created for this.


Are you interested in taking the next step on the path of digital transformation? Ensure correct addressing and be sure to reach your customers. Your job will be easier, too. Lesterius consultants in BeneLux and across Europe will be happy to assist you.

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