When you first form your corporation, it comes into existence as a C Corporation. If you do nothing more, your corporation will remain a C Corporation.
A C Corporation becomes an S Corporation only when special tax treatment is sought by filing Form 2553 with the IRS.
Although a small business lawyer can advise you on the choice of entities, choosing whether to elect S Corporation status is best discussed with your accountant. This is a tax decision, and a tax professional should review your entire financial picture before you make this decision.
New York State S Corporation Status
New York State also requires you file a form to be treated as an S Corporation under State Rules. This form CT-6 Election by a Federal S Corporation to be Treated as a New York S Corporation.
New York City S Corporation Status
However, New York State does not exempt S Corporations from all NYS corporate taxes. Again, you should check with your accountant prior to making this decision
Interestingly, New York City does not recognize S-Corp status at all. If your small business has income from New York City, you will need to pay New York City’s General Corporate Tax.