One of the most common reasons an S-corp return takes longer than it should, or gets filed on extension when it did not need to be, is not the complexity of the corporation. It is incomplete information at the start of the engagement. A CPA can only work with what is in front of them, and when documents arrive in pieces over several weeks, the timeline compresses in a way that creates pressure on both sides and increases the chance of something being missed.
The Form 1120-S filing deadline for calendar-year S-corps is March 16, 2026. Getting your documents organized and to your CPA in early February gives everyone enough time to prepare the return accurately, review it thoroughly, and issue K-1s to every shareholder before the deadline. This post covers exactly what you should bring.
If this is not the first year your S-corp has filed, the prior year return is the single most important document you can bring. It establishes every number the current year return builds on: the opening balance for the accumulated adjustments account on Schedule M-2, the balance sheet opening figures on Schedule L, and the shareholder basis calculations that carried forward from the prior year.
For a CPA taking on a new client, the prior year return is also how they identify whether prior filings were handled correctly and whether any issues, incorrect AAA balances, unapplied suspended losses, or basis errors need to be addressed before the current year return is prepared.
If your S-corp filed on extension last year and the return was completed in September or October, confirm that your CPA has the final filed version, not a draft. Draft and final returns sometimes differ in ways that matter for the current year filing.
Tip: If you are switching CPAs and your prior preparer has not yet transferred your files, request them in writing before your first engagement meeting. A CPA without access to prior year returns is working without essential context, and reconstructing that information adds time and cost to the engagement.
Your CPA needs a complete set of year-end financial statements for the corporation, including:
These should reflect a completed year-end close. If your books are maintained by an outside bookkeeper, confirm the accounts have been reconciled through December 31 before sending anything to your CPA. Arriving with books that are still in progress adds time to the engagement and increases the chance of errors on the return.
Tip: Most accounting software maintains books on a GAAP basis, which is not the same as the tax basis the IRS requires for several key items on the Form 1120-S. Your CPA will make the necessary adjustments, but arriving with clean, reconciled books makes that process significantly faster than arriving with unreconciled accounts that need to be sorted out before the return can be started.
This is the document category that most S-corp owners underestimate. The IRS scrutinizes officer compensation more aggressively on Form 1120-S returns than on almost any other business return. Your CPA needs the payroll records for the year and, more importantly, documentation supporting how the owner-employee salary was determined.
You should bring:
If no written compensation analysis exists, flag that before the engagement starts. Your CPA can help you document the determination, and having that documentation on file before the return is filed is significantly better than producing it in response to an IRS inquiry.
Tip: Health insurance premiums for shareholders owning more than 2 percent of an S-corp are treated differently than premiums for non-shareholder employees. They must be included in the shareholder's W-2 wages and reported separately. A W-2 that does not reflect these premiums correctly produces an incorrect deduction on the Form 1120-S and an incorrect personal return for the shareholder who received the coverage.
Your CPA needs current information for every shareholder who held stock in the corporation at any point during the tax year, including shareholders who sold or transferred their shares before December 31. For each shareholder, bring:
If any shareholder joined or exited during the year, the timing of that change affects how income is allocated between the departing and incoming owner. The daily proration method and the closing of the books method produce different results, and the choice needs to be made before the K-1s are prepared, not after.
Tip: If any shareholder is a trust, estate, or non-resident alien, flag that specifically. Trusts and estates can hold S-corp stock only if they qualify as a specific type of permitted shareholder, and non-resident aliens cannot hold S-corp stock at all. An ineligible shareholder terminates the S-corp election automatically, and the sooner that issue is identified, the more options exist for addressing it.
If the corporation owns depreciable assets, such as equipment, vehicles, furniture, leasehold improvements, your CPA needs the current depreciation schedule showing every asset, its cost basis, the depreciation method being used, and the accumulated depreciation to date.
If the corporation purchased or disposed of any assets during 2025, bring the purchase or sale documentation as well. Asset purchases affect depreciation deductions and potentially Section 179 elections or bonus depreciation under the rules restored by the One Big Beautiful Bill Act for property placed in service after January 19, 2025. Asset sales produce gain or loss that must be characterized correctly, and the character of that gain, such as capital, ordinary, or a combination involving depreciation recapture, depends on the original cost basis and depreciation history.
Tip: If the corporation sold any assets during 2025, do not assume the entire gain was long-term capital gain. Depreciation recapture under IRC Sections 1245 and 1250 converts a portion of the gain to ordinary income taxed at a higher rate on each shareholder's personal return. That recapture amount must be separately stated on the K-1 and cannot be combined with the capital gain portion.
Shareholder loans require careful documentation and separate treatment on the Form 1120-S. If any shareholder loaned money to the corporation during the year, or if the corporation repaid a prior shareholder loan, bring the loan documentation including the original loan agreement, the interest rate, the repayment schedule, and records of any payments made during the year.
Shareholder loans affect debt basis, which is a separate calculation from stock basis and must be tracked on Form 7203. A shareholder who has stock basis of zero may still be able to deduct losses if they have sufficient debt basis from loans made to the corporation. Repayments of loans reduce debt basis and can produce taxable income if the loan basis was previously reduced by prior-year losses.
Tip: Shareholder loans must be properly documented to be treated as debt rather than as additional equity contributions. A loan without a written agreement, a stated interest rate, or a repayment schedule may be reclassified by the IRS as a capital contribution, which has different basis implications and eliminates the debt basis that may be supporting loss deductions.
Beyond the standard financial records, bring any documents related to income or transactions that fall outside routine operations:
If your S-corp operates in Texas, the Texas franchise tax return may be required depending on the corporation's gross revenue. State obligations are not eliminated by federal pass-through treatment, and the timing of state filings often differs from the federal deadline.
Tip: When in doubt, bring it. A document your CPA does not need takes seconds to set aside. A document they needed but did not have can delay the return or require an amendment after filing. The cost of being overprepared is zero. The cost of being underprepared shows up in the timeline.
Organized, complete information delivered early is the single largest factor in getting a Form 1120-S prepared accurately and on time. Every K-1 that flows from that return affects a shareholder's ability to file their own personal return correctly and on time, which means the quality of your document delivery has consequences that extend beyond the corporation.
At TrueView CPA, 1120-S tax preparation for S-corps across Dallas and Texas starts with a clear, tailored document request so nothing is missed and no time is wasted. If you want to get ahead of the March 16, 2026 deadline or need a CPA for your 1120-S preparation this year, we are ready to help.
Preparing for your 1120-S filing? Schedule a call with our tax experts today.
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