S Corporation Rules and Common Pitfalls

Electing S corporation status is only the beginning. The ongoing rules determine whether the election holds and whether the benefits are actually realized. This guide summarizes the areas where owners most often run into difficulty. It is not exhaustive, and details vary by situation.

Keeping the Election Valid

An S corporation election can terminate if the entity ceases to be a small business corporation. Common causes include exceeding 100 shareholders, having an ineligible shareholder such as a partnership or a nonresident alien, or creating a second class of stock. An inadvertent termination can sometimes be corrected with relief procedures, but relief is not guaranteed and can be expensive.

Documents matter. The operating agreement or bylaws, buy-sell agreements, and shareholder agreements should be reviewed to ensure that they do not create rights to distributions or liquidation proceeds that differ among shareholders. Timing differences that are later corrected are often less problematic than fixed rights that differ, but the analysis is technical.

Pro Rata Distributions

Distributions generally need to be made in proportion to ownership. If one shareholder takes a distribution and the other does not, the difference should be addressed promptly through corrective distributions. Recurring non-pro-rata distributions can raise second class of stock questions. Owners should keep a distribution log and reconcile it with the books at least quarterly.

Reasonable Compensation

Shareholders who provide services must be paid reasonable compensation before receiving distributions. This requirement is one of the most frequently examined aspects of S corporation returns. See Reasonable Compensation for S Corporation Owners and How Low Can an S Corporation Salary Go? for how the standard is evaluated.

Basis Limitations

Losses and deductions flow through to shareholders, but they can be deducted only to the extent of stock basis and debt basis, and they are also subject to at-risk and passive activity limits. Distributions in excess of basis can be taxable as capital gain. Owners should track basis annually. Many do not, and the problem surfaces only when a loss is disallowed or when there is a sale. See Shareholder Loans, Stock Basis, and Debt Basis.

Built-In Gains Tax

If a corporation was previously a C corporation, or if it acquired assets from a C corporation in a tax-deferred transaction, it may be subject to a corporate-level tax on the built-in gain of those assets if sold within the recognition period. Owners converting from C to S status should model this before selling appreciated assets.

Passive Investment Income

An S corporation with accumulated earnings and profits from a prior C corporation period can face additional tax, and possible termination of the election, if passive investment income is a large share of receipts for consecutive years. Businesses that hold rental property or investments inside an S corporation with prior C corporation history should be careful.

Owner Expenses and Personal Use

Payments of personal expenses from the company account can be recharacterized as distributions, compensation, or loans. Mixed-use assets and vehicles need clean records. Consider setting up an accountable plan for reimbursing business expenses paid personally. See Accountable Plans for Reimbursing Business Expenses.

Payroll and Filing Compliance

Late payroll deposits, missed quarterly filings, and delayed W-2 forms can generate penalties. The corporation must also file its annual return, and it must issue Schedule K-1 forms to shareholders. Many states have parallel obligations, and some require estimated payments at the entity level.

A Yearly Housekeeping Checklist

1. Review compensation against current market data and hours worked.
2. Reconcile distributions to ownership percentages.
3. Update the basis schedule for each shareholder.
4. Confirm payroll filings and deposits are current.
5. Review shareholder loans and repayment terms.
6. Confirm state registrations and annual reports.
7. Revisit the operating agreement if ownership or economics changed.

Owners who are considering the election should also review S Corporation Election Guide: Form 2553 and Timing. For broader entity questions, see Choosing an Entity Structure at Higher Income Levels.

A Hypothetical Example of a Pro Rata Problem

Imagine two equal shareholders in an S corporation. In one year, one shareholder takes a large distribution to cover a personal purchase, while the other takes none. If the difference is not corrected, the pattern could raise questions about whether the corporation has effectively granted different distribution rights. A prompt corrective distribution to the other shareholder, documented in the books, is often the first step advisors consider. The lesson is not that every timing difference is fatal, but that unaddressed differences are harder to defend than corrected ones.

Talk to Your Advisor Before Ownership Changes

Gifting shares, adding a family member, transferring to a trust, or selling a minority interest can all affect eligibility. Check first, not afterward.

Educational purposes only. This page is general education and is not tax, legal, or accounting advice. Tax laws change and outcomes depend on individual facts, so consult a qualified professional before acting. No result is guaranteed.