Does one pay tax on income or pay tax over income?
I come across both regularly. On seems to be preferred usage, but I'd like to know which is most correct or formal and why.
Does one pay tax on income or pay tax over income?
I come across both regularly. On seems to be preferred usage, but I'd like to know which is most correct or formal and why.
I do not recognise "tax over income" and would not use it.
As you point out, a Google search gives some results for "tax over income". But:
BNC (the British national corpus) has none (it has 10 for "tax on income");
COCA (the Corpus of Contemporary American English) has none (it has 9 for "tax on income");
Google ngrams on "tax on income, tax over income" says "Ngrams not found: tax over income"
This strongly suggests that native English speakers do not say "tax over income". And indeed, if you look at the first few hits for your Google search:
Is that enough evidence?