Unfiled returns are the fastest-growing part of IRS collection: new delinquency investigations rose 291% in FY2025 to 2.5 million. These prospects are usually self-employed, several years behind and afraid of what filing will reveal. Win them with calm, practical messaging about getting back into compliance, a form that sorts them by years unfiled and notices received, and a same-day call.
Why this segment matters now
A taxpayer delinquency investigation opens when someone does not respond to an IRS notice about a missing return. According to IRS Data Book Table 4-1, the IRS opened 2,501,667 of them in FY2025, against 639,143 a year earlier. Tax assessed on delinquent returns secured by collection rose 66% to $29.6 billion. Our full analysis of the FY2025 data covers the rest of the table.
Most resolution marketing still leads with balances and settlements. Very little speaks directly to the person who has not filed for three years and is avoiding the post.
Who the unfiled-return prospect is
- Often self-employed: contractors, gig workers, small business owners whose records fell behind.
- Several years behind: one missed year became three because each year felt harder to start.
- Afraid of the unknown: worried about penalties, an audit or criminal exposure more than a known balance.
- Triggered by a letter: many act only when a notice arrives or a lender, visa or benefits application asks for returns.
What stops them acting
Shame and uncertainty, more than cost. They do not know how bad it is, so they do nothing. Messaging that removes the uncertainty ("here is exactly what happens when you file late, and what usually does not") moves them further than urgency does.
Adverts that work
- Video from a practitioner: "Haven't filed in a few years? Here is what actually happens when you catch up." Calm, specific and credentialed.
- Trigger-based angles: mortgage applications, visa renewals and benefit forms that require filed returns.
- Self-employed angles: "Missing 1099s and receipts? You can still file accurately."
- Never: threats of prison, invented deadlines or promises that penalties will disappear.
Form questions that sort them
- How many years are unfiled? (1, 2 to 3, 4 or more, not sure)
- Have you received an IRS letter about a missing return? Which one, if you know?
- Were you employed, self-employed or both in those years?
- Do you also owe for years you did file?
- Is anything time-sensitive, such as a mortgage, visa or loan application?
Route anyone with a recent notice or a time-sensitive trigger to a person first. Send the rest a short series of reassuring, useful follow-ups.
Follow-up that converts
- An instant text that names your firm and says a person will call shortly.
- A call the same day, with a clear explanation of the first step: transcripts, then a plan for each year.
- A simple checklist of what to gather, sent after the call.
- Two to four weeks of short, useful emails for those not ready, because the next IRS letter often brings them back.
What to measure
Track cost per retained case for unfiled-return work separately from balance-due work. Engagements are often smaller per year but involve several years and frequently lead to ongoing preparation, so measure first-year fees as well. See cost per lead vs cost per retained case.
Questions
How many taxpayers have unfiled returns in 2026?
IRS Data Book FY2025 Table 4-1 shows 2,501,667 new taxpayer delinquency investigations opened in FY2025, up from 639,143 in FY2024, with 3,234,815 open at year end. An investigation opens when a taxpayer does not respond to an IRS notice about a return they have not filed.
What is the best way to advertise unfiled return services?
Lead with getting back into compliance rather than with the debt. Unfiled-return prospects are usually more worried about what filing will reveal than about a balance. Calm, specific video from a credentialed practitioner, a short form that asks how many years are unfiled and whether notices have arrived, and a same-day call work best.
Want these numbers for your own firm? Book a strategy call and we will walk through your lead sources, intake and cost per retained case.