1- Do I need a 2nd EIN for the NY location? no
You will not be required to obtain a new EIN if add other locations or you operate multiple businesses.
2- Can I use my current EIN that was created in NJ for all locations? If doing this, how would the IRS know that another company created in NY is identifying with this EIN?
the IRS doesn't care. all your income gets reported on schedule C. however, the state may require you to obtain a state ID number because toy will have to file state income tax returns for both states
3- Let's say I DO require separate EINs for each state- would each state/EIN/company have completely separate accounting ? you do need separate records because of the state income tax filing requirements
4- I would like to elect S-Corp status- so for my current EIN (NJ)- I would file form 2553 to make that election correct ? And by doing so I would become a W2 employee for the company, correct?
correct and converting to an S-corp would require a new EIN for the corp
5-Again, Let's say I DO require separate EINs for each state, and I have elected S-Corp for each EIN (NJ/NY)- how would I choose which EIN/State/Company to be W2'd from? I live in NJ- so I'm assuming that would be best option for W2?
if you form separate S-Corp s each will need its own EIN. you would need to take a salary from both.
one S-Corp operating in both states creates different issues. (for state taxation of business most states use a formula to allocate income. the factors can be sales in each state, physical property in each state - rented property is included usually at 8 times the annual rental and wages paid in each state. some use 1 some all 3 some give different weight to the factors ) I would suggest you consult a tax pro for this.
