Almost all countries base their taxation system on residency. In short this means residents will be taxed for their worldwide income, while non-residents are taxed only for their source income. Therefore you can say that residency is the most important thing to pay attention to. The Netherlands also has a tax system based on residency. Residency for individuals in The Netherlands is based on facts and circumstances. This means the registration itself is not decisive, but the factual situation will be examined.
For the factual situation the following will be checked:
-In which country do you have your factual place of residency (rented or owned)?
-In which country are your financial ties the closest?
-In which country are your personal ties the closest?
As mentioned above registration itself is not decisive, it can be an indication of the factual situation. Therefore always consult a tax advisor if you plan to (de-)register yourself. It can save you (or cost you) a lot! Residency is also very important for the 30% ruling.