Do I need to complete two tax returns? One for "personal" the income reported on the W2 and one for the LLC?
A single member LLC would be reported on Schedule C and the Schedule attached to your 1040 as business income. You woudl need the additional form but it is not a separate return.
Will the LLC income impact my personal income? i.e. if I get $100K paid and reported in my W2 and make 10K profit before tax from my side business, how will that extra 10K be taxed?
The NET income (profit) from your LLC business will be added to your income and taxed along with your wages (W2).
You will also have Self Employment tax to pay on the NET if you have $400 or more in NET INCOME.
Would the people I send the work to be labeled as independent contractors or just a business expense? would they need to pay taxes in the US if the aren't US Citizens and if they are not working, nor living in the US?
The non US workers can be independent contractors and that is an expense on the Schedule C.
Non US persons not present in the US are not taxed by the US. You would need to secure a form W8 BEN form each of them to show they are non US persons and not subject to withholding.
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