There is no second federal income tax return
People wait for a bill addressed to the company. For a single owner who has not elected to be taxed as a corporation, that bill is not coming. The profit is reported with the person's return. The company name can still appear as the name of the business. The signature is the person's.
Self-employment tax is the Social Security and Medicare tax on net earnings when no employer withheld them. It is part of that same personal return. Forming the company does not mail you a second federal income tax bill for that same profit.
Some states keep a business calendar of their own even when the federal profit is personal. We keep the personal return and that other calendar in separate sentences so nobody pays one of them twice or skips the one that still exists.
What the books have to support
The return is only as calm as the year under it. If draws were called expenses, profit is too low and the self-employment tax is too low with it. If personal spending stayed in the shop, the same thing happens. Cleaning those piles while the month is still open beats finding them when March is already loud.
Categories should describe how this shop makes money. A consultant and a shop that sells goods do not need the same chart, and a chart copied from a template will hide the thing you actually did. We set the chart, then leave it alone so this year can be compared with next year.
Nothing in this explanation is a computation. Your net earnings, other wages, and the forms for the year decide the tax. We prepare that from the closed books. We do not estimate it from the name of the company.
When the shape changes
An election to be taxed as an S corporation moves the profit onto a different form and, once it is really in force, puts wages into the conversation. Until that election is filed and accepted for the year you mean, we do not pretend the wages exist.
That page is the boundary.
A second owner, including a spouse who is actually a member, can change the federal filing too. Helping in the shop is not the same fact as being a member.
The spouse page keeps those apart.
If a notice arrives that treats the company as if it filed something it never filed, we read the notice before anyone pays it. The next step is whatever the letter actually asks for, not a guess from the envelope.
Ask about the personal return
A note about the tax rides on your return is enough for us to start from your file.