Not US.

Never heard of 100% taxing here, what I have seen is raises and promotions ending up in a slightly smaller paycheque. Whether that’s due to other factors such as a higher misaligned bracket of state medical insurance or benefits, union fees, I’m not entirely sure, it was more of a warning to watch your first couple of paycheques after a raise.

To be fair, in places where income taxes are bracketed rather than in smooth percentages, it can happen. It’s much more common with bonuses and heavy OT to jump you up for a single paycheque, though.