[sergiomattei]

That's correct! But federal income tax isn't the only way to get taxed.

1) All goods sold in PR have to pass by mainland US ports, raising living costs significantly. This means re-boarding into a US vessel on the mainland, then sailing to PR if coming internationally.

2) We pay other federal taxes (as freelancer, I pay social security tax among others).

3) Related to #1, customs taxes and levies on all goods transported, paid to the US Treasury.

This is an excellent overview: https://en.wikipedia.org/wiki/Taxation_in_Puerto_Rico