Estimating tax withholdings for freelance next year...

I have a "day job" that gives me a steady paycheck and I plan on doing more freelancing next year. I’m about to fill out a new W-4 form for my "day job". Will I be safe adding in some additional withholding to the W-4 based on 30% of my estimated freelance income? I’ve read some things about paying taxes quarterly, but i think that’s only if I’m not withholding more money from my "day job" paycheck. Any thoughts are advice will be appreciated.

Just seems like it would be easier to get more taken out of every paycheck than to remember to pay every quarter…

If you’re getting a 1099-MISC from freelance income, you will need to make quarterly estimated payments on it, or pay it all at the end of the year with an underpayment penalty. Someone can correct me if I’m wrong, but I’m assuming this is how it works across the board.

The extra money taxes paid via your day job may help offset this, but IRS is still going to hit you with that underpayment penalty I’d assume.

Is there some dollar amount of underpaying that would qualify for the underpayment penalty?

it is if you are off by some % of your previous years income

This link has some helpful info…

I don’t think I’ll underpay. I’m going to make a high estimate as to what I might make next year doing freelance and then if I overpay I’ll just enjoy my refund.
Do you only have to take out taxes for 1099′s and W2′s?

What if you do something for someone but that someone never sends you a 1099…

file if > $600

I file a 1099 and just have it taken from my refund at the end of the year.