Second versus third level domain names

01 January 2018

You see them sometimes when you are searching on the internet: websites with addresses that end in a non-standard extension, such as domain name or domain These are “third level” domain names, as they are known. Domain names that end in .be or .com are known as “second level” domain names: or We explain the difference between the two forms below.

"third level" vs "second level" 

The “third level” extensions are actually sub-domain names which fall under the “real” or “second level” domain name. In the example, is the second level domain name, and hobby is the sub-domain or “third level domain. These sub-domain names can be created by the owner of a domain name without limitation.

There are various reasons for doing so. Some examples include: to set up your own website, or if you want to install a proprietary mail server . Companies can use a sub-domain to create landing pages under their corporate website when they launch specific marketing actions.

When you are the owner of a short and general domain name, such as or, you can sell the sub-domain names to third parties. This sort of internet address is often recommended as an alternative to the real domain name of the country. The Internet company Centralnic has been offering this sort of “third level” domain names on a massive scale for years. The problem with these “third level” domain names is that the owner of the main domain name is also the owner of the sub-domain.  

Centralnic decided recently to scrap a part of these “third level” domain names, i.e. domain names that end in,,,,,,, and The users of these domain names received a message from Centralnic that they would be stopped. The owners must therefore look for another solution to keep their website and e-mail addresses online. Not a nice signal if everyone has known you for years under a domain name ending in one of these extensions.


If you are certain that you want to maintain your own domain name, it is best to opt for a “second level” domain name. .be is managed by DNS Belgium, a non-profit association that has been commissioned by the Belgian government to manage the registrations of all .be domain names. If your favourite domain name is already taken, there are countless safe alternatives.  

A thousand new extensions have emerged recently such, .brussels, .gent, .paris, .Amsterdam, .xyz. An official authority behind all these extensions makes sure that the extension and the domain name under which they were registered will continue to exist. So there is enough choice for the registration of your domain name in a “real” and safe extension.