Illinois Department of Revenue, IT 18-05

David and Judith Doe filed an amended 2010 Illinois individual income tax return in May 2016, seeking a refund based on an increase in their distributive share of research and development credits reported on amended Schedule K-1s from two S corporations. The Department of Revenue denied the refund, asserting the claim was untimely under section 911(a) of the Illinois Income Tax Act, which generally requires a refund claim within three years of filing the original return or one year of payment, whichever is later.

The Federal-Change Exception

The taxpayers argued that their claim was timely under section 911(b)(1), which allows a refund claim within two years after a taxpayer was required to notify the Department of a federal change under section 506(b) — triggered when the IRS alters a taxpayer's income, deductions, or credits. The taxpayers' amended federal return reflected R&D credits from two S corporations that the IRS examined and closed on May 9, 2016; the Illinois amended return followed just three days later, well within the two-year window.

The Department argued the taxpayers' refund was based solely on a state-law recalculation of the Illinois research credit under Schedule 1299-C, not on a federal change, and that the extended limitations period therefore did not apply.

The Illinois Credit Was Tied to the Federal Credit

The administrative law judge granted summary judgment for the taxpayers, reasoning that because Illinois's research credit under section 201(k) is defined by reference to the federal credit under IRC section 41, the taxpayers could not finally determine their Illinois credit until the corresponding federal credit was resolved. Since the same R&D credit amounts reported on the amended K-1s drove both the federal and Illinois recalculations, the refund request was not based solely on a state change, and the extended two-year period under section 911(b)(1) applied. The taxpayers were awarded a refund of $3,663.00.

Significance: This decision clarifies that because the Illinois research credit is calculated by direct reference to the federal credit, a downstream Illinois refund claim tied to an IRS adjustment of a pass-through entity's federal R&D credit is treated as arising from a 'federal change' for statute-of-limitations purposes, giving Illinois taxpayers the benefit of the longer two-year window rather than the standard three-year filing deadline.