IRS non-filer investigations jump 291% in 2025

New federal data shows the IRS opened 2.5 million taxpayer delinquency investigations in fiscal 2025, nearly quadruple the prior year. Tax professionals say the surge means people with unfiled returns have less time before the agency catches up and strips away resolution options.

Why it matters: - The IRS is finding far more non-filers, which raises the risk that people with unfiled returns will face notices, substitute returns and larger tax bills. - Filing compliance remains the gateway to repayment plans and other resolution options, so the timing of action now matters more for taxpayers already behind. - The scale of the backlog suggests IRS enforcement is becoming more automated and more aggressive at matching data.

What happened: - The IRS opened 2,501,667 new taxpayer delinquency investigations in fiscal year 2025, up from 639,143 in fiscal year 2024. - The year-over-year increase was about 291%, or nearly four times as many new cases. - The figures come from the IRS 2025 Data Book, Publication 55-B, Table 4-1, released June 5, 2026. - A taxpayer delinquency investigation, or TDI, is the IRS term for a non-filer case. - A TDI opens when a taxpayer does not respond to an IRS notice of a delinquent return. - The numbers cover all return types for both individuals and businesses.

The details: - The IRS closed 1,317,729 delinquency investigations in TY2025, up from 601,025 the year before. - New cases still outpaced closures, leaving 3,234,815 open investigations at the end of FY2025. - Open TDI inventory rose from 2,050,877 a year earlier, a 58% increase. - The IRS assessed $29.6 billion in additional tax on returns that were not filed on time, up from $17.8 billion in TY2024. - A taxpayer delinquent account, or TDA, is different from a TDI because a TDA involves a filed return or an assessed tax with a balance still owed. - Peter Kici, an IRS Enrolled Agent and founder of Orlando-based Tax Debt Relief Group, said many people first think they simply owe money, but transcript reviews often reveal multiple unfiled years underneath. - Kici said the IRS generally will not seriously consider an installment agreement, currently not collectible status or an offer in compromise until missing returns are filed. - Kici said people should file before the IRS files substitute returns, because substitute returns usually miss deductions and credits. - Tax Debt Relief Group works with individuals and small businesses on unfiled returns, IRS collections and tax debt resolution. - Kici said he offers free, confidential consultations.

Between the lines: - The size of the jump points to a stronger IRS emphasis on automation and data matching rather than a one-off spike. - Taxpayers who wait are likely to lose leverage, because the IRS can move from missing-return notices to substitute filings and collections. - The data also suggests the backlog is growing faster than the agency can clear it, which can widen the gap between non-filing and enforcement.

What's next: - More taxpayers with missing returns are likely to be identified as the IRS continues using data-driven enforcement tools. - People with unfiled returns may face fewer options if they wait until after the IRS has already opened a case or prepared a substitute return. - Tax advisers are likely to keep urging taxpayers to file voluntarily before the IRS takes the first formal step.

The bottom line: - The IRS is moving faster on non-filers, and the cost of waiting is rising.