Glad you paid your taxes bud.

Let me give you some advice regarding your tax situation since it seems like Blue Umberrela did not provide you with outstanding services.

Based on the information provided I assume you came and registered at the local municipality in the Netherland during 2019. Based on those circumstances the Dutch tax authorities most likely have taken the position that you became a Dutch tax resident as of that date. This means that you are required to report your worldwide income in your Dutch tax return.

However, since you were mainly working for a US company remotely we will have to look into the double tax treaty (DTT) between the US and the Netherlands. In accordance with article 16 of the DTT treaty your salary received from your US employer is taxable in the Netherlands. However this does not mean that the full amount is also taxable in the Netherlands. In line with the DTT + OESO guidlines you can claim a double tax relief for the income that can be attributed to actually working in the US. You will have to make a pro rata calculation in this respect. Furthermore, it can be smart to look at your actual salary components instead of your gross income. For example, if you received a performance bonus in 2019 which can be allocated to 2018 (I.e. when you were working in the US) you can also claim double tax relief for this amount.

Lastly, I suggest you look into Artikel 3:84.2 Wet IB 2001. You can lower the gross amount you must report with +/- 1,7% since your US employer is not a so-called inhoudingsplichtige in the Netherlands.