Disregarded LLC Read their form beside last year's return
Two papers. Their wording, and the return that was signed. Everything else can wait.

The short list
Checklists for this moment love to grow. Certificate, operating agreement, bank statements, a prior-year organizer, a screenshot of every setting. You will want those papers if we close a month. You do not need them to answer a vendor. You need their sentence, exact enough that we can see which path their software will take, and the return you signed, exact enough that we can see which path the tax life already took.
If the return is a personal return, say so and say whether the activity was a trade, a rental, or something else. If it was a partnership or a corporate return, say the face of it. If you signed an extension and the return is not finished, say that. An unfinished return is still a fact. It is not a blank check to guess the box.
When no return exists
Then the pair is broken, and the honest move is to stop. A company that has never filed is not answered by a vendor's default. It is answered by figuring out whether a return was due at all, and as what. That is a different meeting, and it should happen before their form is finished. Leaving the box blank is the bridge between the two meetings. Guessing is how a missing return becomes a wrong information form.
How to send the pair
A photo of the vendor sentence and a photo of the first page of the return, with identification numbers covered, is plenty. Or describe both in the note and bring the pages to the call. We are not building a portal you have to learn. We are reading two sheets.
What stays in the drawer
The operating agreement, the bank statements, and last year's organizer are real papers. They belong in a close. They do not belong in the first answer to a vendor. Bringing them all forward feels thorough and usually delays the only comparison that matters. Their sentence says which path the software will take. The return you signed says which path the tax life already took. Put those two on the table. Leave the rest in the drawer until a month is actually being closed.
If the return is a personal return, say whether the activity was a trade, a rental, or something else you can name in ordinary words. If it was a partnership return or a corporate return, say the face of it. If you signed an extension and the return is not finished, say that too. An unfinished return is still a fact. An unfinished return still forbids a guess on their form. If no return has ever been filed, the pair is broken and the honest move is to stop. A company that has never filed is not answered by a vendor's default. The meeting becomes whether anything was due, and as what. A blank box is the bridge to that meeting.
A photo of their sentence and a photo of the first page of the return, with identification numbers covered, is plenty to start. You can also describe both in the note and bring the pages to the call. There is no portal to learn. We are reading two sheets, and the reading is allowed to end in a pause. A pause, with the box still blank, is a complete result. Guessing, in order to feel done, is how a missing return becomes a wrong information form in someone else's January. Two sheets, and a pause if they disagree, are a complete night. Two sheets on the table can close the evening without a third stack.
Send the pair, or say there was no return
If nothing was filed, say that in the first line.
You will be talking to the Steven Palmieri practice.