When in doubt – go to the instructions. See the instructions for Form 1120S Line 12:
Don’t deduct the following taxes on line 12.
- Federal income taxes (except for the portion of built-in gains tax allocable to ordinary income) or taxes reported elsewhere on the return.
…
- Taxes not imposed on the corporation.
…
So no, Federal income taxes paid for the prior year are not a deductible expense for the corporation.
Also, worth mentioning that S-Corp is a pass-through entity and will only pay income taxes in a very exceptional situation which is unlikely to be your case. I suspect when you say “I paid income tax”, you literally mean yourself, on your individual tax return. As such – that’s not even an expense to the corporation, deductible or not – it’s your personal expense.
