When I enrolled with my new employer's HR system on Dec 1st, I mistakenly filed a W4 claiming to be exempt from federal taxes, which I'm not.
As a result, my first (Dec 15th) paycheck was quite higher than I expected, since no federal taxes were withheld from it. I've already filed a new W4 with the right information, so federal taxes should be properly withheld from my next paychecks going forward.
My question is: should I proactively pay the federal taxes that should have been withheld from my first paycheck? And if so, how should I go about that (in particular, how do I know the amount that should have been withheld, and how do I pay it to the IRS)?
Or should I simply wait to file my regular tax return next year, at which point I would pay the taxes I should have paid on my first paycheck with no extra penalty?
Based in the US, company HQ in CA, but I live & work in WA.