Tax Court Denied Deductions for California Resident

A court ruling confirms that without proper records, California taxpayers risk losing significant business deductions.

Updated on Oct. 2, 2026 in Taxes

Isometric editorial illustration of a single thick, empty binder standing on a shelf, representing the need for tax documentation. — The U.S. Tax Court ruled that a California taxpayer failed to substantiate business deductions, affirming IRS deficiency assessments for tax years 2014 through 2017. AI Illustration. Upload story photo >

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On September 2, 2026, the Tax Court issued a decision in Risan, TC Memo 2026-78, upholding IRS disallowances of tax deductions for a California taxpayer. The ruling impacts how households must substantiate business-related claims during an audit.

Why it matters

The decision underscores the necessity of maintaining rigorous records to support tax deductions, as the taxpayer failed to prove claims for his business expenses. It also highlights the failure of the IRS to treat the individual and his corporations as a single entity under California law.

The taxpayer faced scrutiny over records related to the ownership of 700 to 1,000 vintage guitars and an alleged $150,000 ransom demand for missing business documents. These figures highlight the scale of substantiation issues impacting taxpayers in California.

The players

IRS

The federal agency responsible for tax collection, auditing individual and corporate returns, and enforcing compliance.

Tax Court

The specialized judicial body that hears disputes between taxpayers and the IRS regarding tax deficiencies.

The details

The IRS audited the taxpayer for individual returns from 2014 to 2017 and corporate returns from 2016 to 2017, finding that corporate funds were often used for personal credit card payments and living expenses. Despite these findings, the court rejected the IRS argument that the taxpayer and his corporations functioned as a single alter ego entity. Ultimately, the lack of sufficient documentation to support the validity of claimed deductions led the court to affirm the deficiency assessments.

2014-2017: Tax years audited for individual returns.
2016-2017: Tax years audited for corporate returns.
September 2, 2026: Tax Court issued decision Risan, TC Memo 2026-78.

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Money Landscape

This case sits within the broader landscape of tax enforcement where the IRS increasingly challenges intermingled personal and business finances. It serves as a reminder of the strict evidentiary standards required to maintain corporate tax status versus individual income tax obligations.

Households should treat all business expenses as auditable by maintaining clear receipts and separate accounts for corporate and personal funds. Consult with a qualified tax professional to ensure your documentation practices meet the requirements set by recent court rulings.

The takeaway

The primary insight is that meticulous record-keeping is the only defense against the disallowance of substantial tax deductions. Ensure your business and personal expenses are distinct, and discuss your current record-keeping strategy with a tax professional.