For a single member LLC a tax return is not due until the first year the business is officially "open for business". Now since a SMLLC is registered at the state level, you need to take care here if the state taxes personal income. Depending on the state, when you initially register a SMLLC it's status by default is "active", meaning that as far as the state is concerned, you were officially "open for business" on the date of registration, or whatever date you specified you'd be open for business. So it's possible the state could be expecting business income/expenses to be reported on your state return for that year, and you'll hear from them if it's not.
It can cause what "appears" to be a catch-22 situation. That's where you can't open a business account without that state registration form, but your business will not be active until sometime after the account is established.
I know when I first registered my SMLLC in FL, I made sure the initial status was "inactive" so that I could open my business checking account. Then once everything was ready I paid the $10 fee to change the status from inactive to active and I was off and running. This was back in 2004-2005 for me, and FL state law on this has changed quite a bit since that time.
