Quick overview

IRS letters and notices are how the agency communicates about assessments, collections, audits, and requests for information. Each letter includes a deadline or response window. Deadlines can be as short as a few weeks for collection or appeal rights, or longer when the IRS requests documentation. Always read the top of the letter where the return-by or reply date is printed.

In my practice advising taxpayers for over 15 years, I’ve seen timely responses stop liens, avoid levies, and resolve disputes with minimal cost. Below I summarize common notice types, typical timelines as of 2025, recommended actions, and realistic expectations based on IRS procedures. Where possible I cite IRS guidance — for binding, case-specific advice consult a CPA, EA, or tax attorney.

Why deadlines matter

  • Missed deadlines can trigger penalties and interest, accelerate collection actions (liens and levies), or forfeit appeal rights.
  • Some deadlines are procedural and short: for example, collection appeal windows or the time to petition the U.S. Tax Court after a Notice of Deficiency are time-limited.
  • Quick responses let you request more time, set up payment plans, or present documentation to prevent escalation.

Authoritative sources: see IRS guidance on responding to notices (IRS.gov — “Respond to a notice or letter”) and the Notice of Federal Tax Lien process (IRS.gov — “Notice of Federal Tax Lien”).

Common IRS letters, what they usually mean, and typical timelines

Note: the IRS prints the specific date or number of days on each notice. Below are common ranges you’ll see in practice; treat them as starting points, not substitutes for the date on your letter.

  • CP2000 (proposed changes to income/amount due): typically 30 days to respond. You can agree, disagree, or provide documentation. Failure to reply often results in the IRS making the proposed change and issuing a bill. (IRS.gov — “CP2000 and other notices”)

  • Balance-due notices (examples: CP14, CP501/CP503): usually 30 days to pay or contact the IRS. Staged notices may follow with increasing urgency leading up to collection actions.

  • Collection notices and final notices of intent to levy (CP90, CP297, LT16): many give 30 days to respond or request a Collection Due Process (CDP) hearing. For NFTL (Notice of Federal Tax Lien) you typically get a 30-day window to request a CDP hearing after the lien notice is filed. (IRS.gov — “Collection: Liens and Levies” and “Notice of Federal Tax Lien”)

  • Notice of Deficiency (90-day letter / statutory notice): this is unique. The IRS gives 90 days to petition the U.S. Tax Court if you live in the United States (150 days if you are abroad). Do not miss this window — it is the only way to litigate the deficiency in Tax Court without first paying the tax. (IRS.gov — “About Notice of Deficiency”)

  • Audit-related correspondence:

  • Correspondence audits (paper): often allow 30 days to submit documents.

  • Field audits and more formal examinations: the timeline depends on the scheduling letter — early contact is crucial so you can gather records. See our guide on understanding audit types for preparation strategies: Understanding Field Audits vs Correspondence Audits.

  • Refund or identity-verification letters (e.g., CP01A, or identity verification notices): response timelines vary but can be short (typically 30 days) when the IRS needs proof before issuing a refund.

  • Installment agreement and Offer in Compromise correspondence: deadlines to respond vary by program; offers and partial-pay agreements include clear dates in the packet.

Practical step-by-step: what to do when you get a letter

  1. Read the full letter immediately. Look for the reply-by date and the specific actions requested.
  2. Don’t panic. Many notices are informational or resolvable with documentation.
  3. Check authenticity. Confirm the notice is from the IRS (IRS.gov provides images and guidance on authentic notices). Scams use fake letters — never give personal information unless you initiated contact using IRS phone numbers or secure portals. (IRS.gov — “Tax Scams/Consumer Alerts”)
  4. Gather documents. Locate returns, W-2s, 1099s, bank records, and any substantiation the letter requests.
  5. Respond in writing before the deadline, and always keep copies and proof of delivery (certified mail, electronic receipt).
  6. If you need more time, call the number on the notice immediately. The IRS may give a short extension or explain options (installment agreement, offer in compromise). Don’t assume an extension is automatic.
  7. Consider representation: Form 2848 (Power of Attorney) allows a CPA, EA, or attorney to represent you. Representation can reduce errors, speed responses, and manage appeals.

Special deadlines and high-stakes notices

  • Notice of Deficiency: 90 days (U.S.) / 150 days (abroad) to file a petition with the U.S. Tax Court. If you miss it, your judicial options narrow and you may need to pay and then sue for refund in district court.
  • CDP (Collection Due Process) rights: typically you must request a CDP hearing within 30 days of the lien or levy notice to preserve appeal and collection-review rights.
  • Statute of limitations: the IRS generally has three years from the filed return to assess additional tax; however, exceptions (substantial understatement, fraud, no return filed) extend or suspend that period. These statutory rules differ from the administrative reply windows on notices and are separate timelines to track.

For further reading on appeals and converting audits into appeals conferences see our FinHelp articles: How to Convert a Paper Audit into an Appeals Conference and IRS Tax Liens: How They Work and How to Get Them Released.

Common mistakes I see in practice (and how to avoid them)

  • Waiting until the deadline: Respond early. It gives you time to gather missing docs and fix errors.
  • Ignoring authenticity checks: Confirm via IRS.gov if you’re unsure. Scammers target refund-seeking taxpayers using fake deadlines to push payment.
  • Failing to document communications: Always get and keep written confirmations. If you call, request a callback number, employee name, and follow up with a mailed record.
  • Not using representation when stakes are high: A small retainer for a qualified representative can preserve rights and avoid costly mistakes.

If you miss a deadline

  • Contact the IRS immediately and be honest about why you missed it. In many cases the IRS will accept late responses if you act quickly and show reasonable cause.
  • For missed tax-court petitions (Notice of Deficiency): consult a tax attorney right away — remedies are limited and timing is critical.
  • For collection or levy deadlines: you can often halt or reverse a levy by promptly arranging payment, an installment agreement, or proving hardship; but reversing a levy is not guaranteed and is time-sensitive.

Recordkeeping and prevention tips

  • Keep organized records for at least seven years for complex items (three years is the general statute for most returns, six years for substantial omission issues). See our guide on recordkeeping for audits and refunds: Top Tax Recordkeeping Practices to Speed Up Refunds and Audits.
  • Use a central folder (digital and physical) for IRS communications and note the date you received each notice.
  • Set calendar reminders well before the IRS reply date — aim to respond 7–10 days earlier.

When to get professional help

  • You receive a Notice of Deficiency, a final notice of intent to levy, or a Notice of Federal Tax Lien.
  • The tax amount involved is large or you suspect identity theft or fraud.
  • You’re unsure how to respond to CP2000 or audit requests.

In my experience, calling a tax professional early often reduces total cost and emotional stress. A practitioner can prepare submissions correctly, request timely extensions, and represent you in appeals or CDP hearings.

Useful IRS resources (authoritative)

Final rules of thumb

  • Always read the notice headline and the reply‑by date first.
  • Treat 30 days as a common deadline but verify your letter — some notices carry shorter or unique statutory periods.
  • Keep records of every submission. Proof of timely response is your best defense.

Professional disclaimer: This article is educational and does not replace personalized advice. For specific legal or tax guidance, consult a licensed CPA, enrolled agent, or tax attorney. The IRS links above reflect guidance current as of 2025.

If you want, I can prepare a short checklist you can print and keep with your tax documents to use whenever you receive an IRS letter.