I am currently employed full-time but the rest of my time is spent on my startup LLC. I was wondering when the US taxes deadline is for LLCs and, more importantly, what the filing process is when you have only expenditures and $0 revenues. I had heard from a friend that filing for business was on March 15 but filing personal taxes was due April 15. Any guidance would be highly appreciated in this matter.
I am not a CPA, but I have two LLC's of which I am the only employee.
On the federal level you file your LLC when you file your personal taxes, so that would be April, you can read more are irs.gov. Your filing should be pretty straight-forward if you are zero revenue.
The IRS would like you to file quarterly estimated payments of $0 so they can keep an eye on you, but legally you should only have to mention the LLC on your personal filings as a $0 company. This changes if you want to claim expenses for the LLC, but if you don't it's pretty simple.
Now, state and local taxes all depends on where you are. In my locality I have to file by March 1st, whether there was revenue or not.