Blog: Is the address management in your organisation ready for the new municipal mergers?

Discover the full impact of the new merger wave on your address management.

On 1 january 2025 (and 2 December 2024), our country will undergo a new wave of mergers.  Flanders and Wallonia will get a combined total of 14 new municipalities. How will this change affect the address management in your organisation? 

What exactly will happen? 

On 1 January 2025, 28 Flemish municipalities will merge to form 13 new ones. In Wallonia, just two municipalities will merge on 2 December 2024. The 14 merger operations have an important impact on organisations that manage a large number of addresses. Changes have been announced for as many as 500,000 addresses!

In most cases, the operation is limited to a change of municipality name. However, for a large number of addresses the street name will change as well, since two identical street names in one municipality is not allowed. For some addresses, this change will be combined with a clean-up operation to make house numbers or box numbers more logical. Postcodes remain the same in all cases.

Last but not least, the residents of Zwijndrecht will move from the Province of Antwerp to East Flanders. Their municipality will be included in the new municipality merger in East Flanders combining Beveren-Kruibeke-Zwijndrecht.


Risk of losing information 

If your organisation works with address information, make preparations in good time. Depending on the number of addresses in your system, you can do this either manually or automatically.

The impact of these mergers can be considerable, since in many organisations a lot of other information may be linked to one address. For example, customer data, customer history, a telecom connection, the warranty period of a new roof or summary of service interventions.

“It is essential to switch old addresses correctly to the new ones in order to avoid losing any information."

It is essential to switch old addresses correctly to the new ones in order to avoid losing any information. After all, if your system sees an amended address as a new one, you could immediately lose all the history and linked information.


Converting addresses with a difference file

A first way to transform all your addresses is by using a difference file. This allows you to change all address correctly in one go.

Does your current database of addresses contain errors, such as incomplete street names, spelling mistakes or different languages? Then it is strongly recommended to combine this transition with an address normalisation. As such, you align to the official addresses first, before converting them with the difference file.


You can come to GIM for both address normalisation and a difference file from Belmap for all Belgian addresses that will change on 1 January 2025.

No sleepless nights thanks to the "Stable Identifier" 

An alternative and smart solution is to connect your data not to the address, but to a code that does not change, whenever you are referring to the same building.  Then, an extra field in your address file serves as a "stable identifier". Change the street name, then the address changes with it, without losing all the other information.  As such, your address database remains up to date in a smart way and merging municipalities or other changes don't give you a headache.

GIM customers who use Belmap Master Address Management are rest assured. All new addresses are automatically included, without losing information. 


Take care with statistics! 

Do you make spatial analyses for reporting or marketing purposes, for instance? Since the link between municipalities, boroughs and statistical sectors will change, aggregated data or NIS codes change too. The merged municipalities will each be given a new NIS5 code, while the codes in the underlying statistical levels (NIS9) do not change.

So, if you want to do correct analyses you must start by swapping your historic data to the new NIS codes. Again, Belmap can help you.


Do it yourself or use a partner?

Whether you are best doing this operation yourself or seeking support from an address expert depends on your situation:

  • What is the possible impact of the mergers on your organisation?
  • Which possible (commercial) risks do you run if you don't get your database of addresses up to date in time or accurately?
  • How great is the risk of lost information?

The bigger the impact and possible consequences, the more interesting it is to turn to an external partner with expertise in data management and the appropriate geographical insights and tools.

Do you have any questions about impeccable address management?  Please contact our experts for more information.


Bruno De Lat 
Product Manager Belmap at GIM 






Further reading: 


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