I moved to the Netherlands five years ago from the US - dealing with the tax agency here is such a breeze compared to the IRS.
Firstly, digital filing is the norm and for "simple" returns, just works.
Secondly, if you ever have a question, you can just call the tax authority on their free phone number, and pretty much ask them anything related to individual or business tax returns.
It was heads and shoulders above most interactions I’ve had with with ISPs, big banks, and the like, where you get transferred around between departments that don’t seem particularly interested in helping you out....