1. What Can Trigger a Corporate Tax Dispute with the IRS?
The IRS may question reported income, business deductions, or accounting methods. A corporation must determine whether its position lacks adequate documentation or conflicts with federal tax rules.
Disputed Deductions and Capital Expenses
IRC § 162 generally permits deductions for ordinary and necessary business expenses, subject to statutory limits. The IRS may challenge an expense when records do not establish its amount, purpose, or connection to business operations.
A payment recorded as an operating expense may instead require capitalization under IRC § 263. Contracts can establish what the company purchased, while invoices, payment records, and accounting entries help determine its cost and tax treatment.
Examining the IRS Adjustment Report
An examiner's proposed adjustment does not necessarily establish a final liability. Compare each disputed item with the filed return and the records used to prepare it.
Before responding, identify:
- The corporation, tax year, and proposed adjustment.
- The IRS's factual and legal reasons for the change.
- Documents supporting or contradicting the reported treatment.
- The notice type and applicable response deadline.
A corporation facing an examination can also review its options for tax audits and adjustments.
2. Who Is Liable after a Corporate Tax Adjustment?
Federal tax classification determines whether an adjustment primarily affects the corporation or its shareholders. Ownership alone does not make an individual liable for ordinary corporate income tax debts.
C Corporation and S Corporation Tax Treatment
Under IRC § 11, C corporations generally pay federal income tax on their taxable income. IRC § 1366 generally passes S corporation income, losses, deductions, and credits through to shareholders. Certain S corporations still owe federal entity-level taxes.
| Issue | C Corporation | S Corporation |
|---|---|---|
| General federal taxation | Corporate-level income tax | Pass-through taxation |
| Income adjustment | Generally affects corporate tax | Generally affects shareholder tax |
| Primary tax documents | Form 1120 | Form 1120-S and Schedule K-1 |
| Potential liability | Additional corporate income tax | Shareholder tax or certain entity-level taxes |
General federal taxation
- C CorporationCorporate-level income tax
- S CorporationPass-through taxation
Income adjustment
- C CorporationGenerally affects corporate tax
- S CorporationGenerally affects shareholder tax
Primary tax documents
- C CorporationForm 1120
- S CorporationForm 1120-S and Schedule K-1
Potential liability
- C CorporationAdditional corporate income tax
- S CorporationShareholder tax or certain entity-level taxes
An S corporation's revised income may change a shareholder's taxable income even without a cash distribution. Loss adjustments can also raise shareholder basis and other deduction limitations.
When Corporate Owners Face Personal Liability
Shareholders generally do not become personally liable for a corporation's ordinary federal income tax deficiency merely because they own shares or manage its operations.
Separate statutes may impose liability for different obligations. Under IRC § 6672, an individual who was responsible for collecting, accounting for, or paying over certain trust fund taxes and willfully failed to do so may face a trust fund recovery penalty.
This provision concerns specified unpaid trust fund taxes rather than an ordinary corporate income tax adjustment. The nature of the debt must be established before assessing an owner's exposure.
3. How Can a Corporation Dispute an IRS Adjustment?
A corporation may challenge a proposed adjustment during examination, request administrative Appeals review when available, or petition the U.S. Tax Court after receiving a valid statutory Notice of Deficiency. Each stage follows different rules.
Examination Responses and Administrative Appeals
During examination, a corporation may submit missing records, correct factual errors, and explain why its tax treatment complies with federal law.
If the IRS issues a qualifying 30-day letter, the corporation generally has 30 days from the letter's date to request review by the IRS Independent Office of Appeals, subject to the notice's instructions and applicable procedures.
A written protest should identify disputed items, supporting facts, and legal arguments. Some disputes qualify for simplified protest procedures.
An IRS tax controversy attorney can evaluate the available administrative procedures and whether the dispute presents factual or legal issues.
Notice of Deficiency and Tax Court Deadlines
Under IRC § 6213(a), a corporation generally has 90 days after the IRS mails a statutory Notice of Deficiency to petition the U.S. Tax Court. The period is generally 150 days if the notice is addressed to a person outside the United States or the taxpayer is outside the country when the notice is mailed.
A timely petition generally permits the corporation to contest the proposed deficiency before payment. Special rules may affect deadline computation, including weekends and legal holidays.
IRS discussions do not ordinarily extend the statutory petition deadline. The corporation should verify the notice date, designated deadline, and proper petitioner before filing.
4. How Do California Corporate Tax Disputes Differ?
An IRS adjustment may also affect a corporation's California tax obligations. The Franchise Tax Board (FTB) applies separate state tax rules, reporting requirements, and administrative deadlines.
California Franchise Tax and Federal Adjustments
California taxes corporate income under its Revenue and Taxation Code, but state treatment does not always match federal law.
California generally imposes a 1.5% tax on S corporations subject to its corporate tax rules, despite their federal pass-through treatment. A minimum franchise tax of $800 also generally applies to corporations doing business in California, subject to applicable exceptions.
A final federal adjustment may trigger separate California reporting obligations, generally within six months under Revenue and Taxation Code § 18622. The corporation should determine whether the federal change affects its California tax base, credits, or previously filed returns.
FTB Protest and Appeal Periods
A California Notice of Proposed Assessment generally provides 60 days from the notice date to file a protest with the FTB.
If the FTB issues a Notice of Action affirming an assessment, the taxpayer generally has 30 days from that notice date to appeal to the Office of Tax Appeals.
A federal dispute does not automatically preserve California protest or appeal rights. Businesses should track the two proceedings separately and evaluate related state tax compliance obligations.
5. Review a Corporate Tax Dispute with SJKP LLP
SJKP LLP's attorneys review disputed IRS adjustments, corporate tax records, and federal or California notices. A corporate tax attorney in San Diego can assess available challenges and filing deadlines before a business responds.
13 Nov, 2026
