What the IRS says: “The IRS is formally proposing a tax increase; you have 90 days to petition the United States Tax Court if you disagree.” Here’s what it actually means, your deadline, and exactly how to respond.
This is the legal endpoint of the CP2000 process — the '90-day letter.' It's the one deadline in tax procedure with no extensions and no second chances: if you don't petition Tax Court within 90 days (150 if outside the US), the IRS assesses the tax and moves to collect it, and your only remaining route is paying first and suing for a refund. You can still resolve it with the IRS during the 90 days — but only the Tax Court petition stops the clock.
Notice family: Underreporter & Audit — The IRS thinks your return doesn't match its records — or wants to examine it. These notices carry hard response deadlines, and a written response with documentation is exactly how they get resolved.
90 days — to petition Tax Court — no extensions, 150 days if the notice was addressed to you outside the US.
Counted in calendar days from the notice date. The exact respond-by date printed on your notice always controls — check page 1.
Calendar day 90 from the notice date today — it is jurisdictional, and the petition must be FILED by then
If you disagree: file the Tax Court petition (there's a simplified small-case procedure under $50,000) — you can settle with IRS Appeals afterward
Simultaneously send the IRS your documentation — cases regularly resolve before trial
If you agree: sign Form 5564 waiver so interest stops accruing sooner
Respond on two tracks: the petition preserves your rights; a documented letter to the IRS (Form 5564 if agreeing, evidence package if not) resolves the substance. Never let the 90 days lapse while waiting for the IRS to answer correspondence.
Describe the notice and your side of it — use placeholders, never your SSN or account numbers (the letter keeps [YOUR NAME]-style fields so you fill in the real details privately before mailing). A mail-ready draft with an enclosure checklist comes back in ~20 seconds.
Your IRS response letter draft will appear here.
The IRS is formally proposing a tax increase; you have 90 days to petition the United States Tax Court if you disagree. In practice: This is the legal endpoint of the CP2000 process — the '90-day letter.' It's the one deadline in tax procedure with no extensions and no second chances: if you don't petition Tax Court within 90 days (150 if outside the US), the IRS assesses the tax and moves to collect it, and your only remaining route is paying first and suing for a refund. You can still resolve it with the IRS during the 90 days — but only the Tax Court petition stops the clock.
You generally have 90 days — to petition Tax Court — no extensions, 150 days if the notice was addressed to you outside the US. The respond-by date printed on your own notice always controls.
Respond on two tracks: the petition preserves your rights; a documented letter to the IRS (Form 5564 if agreeing, evidence package if not) resolves the substance. Never let the 90 days lapse while waiting for the IRS to answer correspondence.