IMTneTU in the Wilds.. taxes are paid on planetary folk; travellers, free Traders, Guild ships pay fees. Planets with C+ class ports, with low and moderate populations try not to soak the interstellar folk too much, becuase then the price of shipping gets passed onto them.
I have however, one High pop world, TL-8, C-class world in our region of our TNE 1210 campaign that the Guild calls "home", and the local govt. there does its best to soak with incrementalism fees everyone
not of the Guild with everything from fees for scoop diving (using a natural resource!), refining fuel (protect our insystem refining scoop-diver's gild!), and taking off without selling with import & export tariffs (sell your salvaged relic tech here, or pay to carry it off!), to fees for brokering your own cargo (Use our brokers, or pay to sell it yourself if you think you'll get a better price).
All of these system fines are naturally enforced by the home system's impressively large, missile doctrine heavy non-jump system defense force, SPA security Customs folk, and Orbital Station bound Star Marines.
Prior to MTneTU, taxes weren't something most of the players worried about. Window dressing. Only those with shares in megacorps, properties, and planetary assets had to worry about that, and most of our players were worried about making the next repair bill, keeping the ship aloft, and out of the hands of the creditors.
Now..a few of my players have managed to parlay their pre-1117 cash wealth into current local currencies, and are banking on various worlds they've passed through..On April 15th next game year (1211), we'll see how they pay those local govt.s local income taxes!