Understanding the timeline after an IRS notice: deadlines and next steps

Receiving an IRS notice can feel urgent and confusing. The most important practical fact: the notice itself contains the deadline you must meet. Deadlines vary by notice type and by whether the IRS is proposing an adjustment, demanding payment, or starting collection. In my 15 years as a CPA and CFP®, I’ve seen that quick, documented action reduces penalties and prevents escalation to liens or levies.

Below I explain common timelines, statutory time limits that affect your case, how to respond, what happens if you miss a deadline, and realistic next steps you can take immediately. I cite IRS guidance where appropriate so you can verify the details (see authoritative links at the end).

Common notice timelines and what they mean

  • Routine CP letters (CP2000, CP501, CP14, etc.): Typically 30 days

  • Many commonly received IRS letters — for example CP2000 (proposed changes to your return) or CP501/CP14 (balance-due notices) — include a 30‑day period to respond, agree, or pay. The IRS uses this window to allow taxpayers to provide documentation or to dispute the proposed change (IRS CP2000 page) (IRS Understanding Notices).

  • Notice of Deficiency (a “90‑day” letter): 90 days to petition Tax Court

  • If the IRS cannot resolve an issue administratively, it may issue a Notice of Deficiency (often called the 90‑day letter). You have 90 days from the mailing date (150 days if you are outside the U.S.) to file a petition with the U.S. Tax Court if you want judicial review before paying the assessment. This is a strict statutory deadline; missing it limits your options to challenge the tax in court (IRS – Notice of Deficiency).

  • Collection notices and due dates: action expected quickly

  • Collection notices demanding payment or proposing levy action will state a payment due date and describe collection options (installment agreements, offers in compromise, or requesting a collections hearing). Interest and penalties begin to accrue on unpaid amounts from the original due date of the tax.

  • Identity verification and other special notices: variable but usually short

  • Identity verification notices or requests for documents often include a short response window (commonly 30 days). Identity‑verification steps are time-sensitive because delays can affect refunds and account holds.

  • Statute of limitations on assessment: generally 3 years

  • The IRS generally has three years from the date you filed your return to assess additional tax. There are exceptions (substantial understatement, fraud, or no return filed) that extend this period (see IRS statute of limitations guidance).

  • Collection statute expiration date (CSED): 10 years from assessment

  • Once tax is assessed, the IRS typically has 10 years to collect it. After that CSED passes, the IRS can no longer enforce collection through levy or garnishment (except for a few limited exceptions).

Quick checklist: what to do the day you get a notice

  1. Read the notice completely. Note the deadline and the action requested.
  2. Confirm the notice’s authenticity (mailing address, notice code, and your name/SSN). If unsure, verify with the IRS guidance or our article on how to verify authenticity (see internal link below).
  3. Don’t ignore it — mark the deadline and add a calendar reminder two weeks earlier.
  4. Gather supporting documents now (W‑2s, 1099s, receipts, canceled checks).
  5. Decide how you’ll respond: a written mail response with copies, calling the phone number on the notice, or seeking a tax professional’s help.
  6. If you need more time, call the number on the notice immediately and ask. The IRS sometimes grants short extensions for good cause.

How to prepare and send a response (best practices)

  • Use the notice as your roadmap: include the notice code and the taxpayer ID at the top of your reply.
  • Send copies, not originals. Label and paginate documents so an IRS reviewer can match them to your explanation.
  • Mail by certified mail with return receipt or use an IRS-provided address/online tool if the notice allows electronic submission. Keep proof of mailing and delivery for your records.
  • If you call, record the date/time, name/ID of the IRS employee, and a short note of the conversation.
  • Use plain language and stick to facts. If you dispute an amount, show the math and attach source documents.

If the notice proposes changes (e.g., CP2000)

  • You can agree and pay the balance due, agree and request an installment plan, or disagree and provide documentation.
  • Don’t file an amended return if the CP2000 is accurate; instead respond to the notice with documentation and explanations. If you disagree and want to propose an alternative calculation, include that in your response.

What happens if you miss a deadline?

  • Missing the stated deadline typically increases risk: penalties and interest will continue to accrue, and the IRS may enter its proposed changes or proceed with collection.
  • For routine CP letters, the IRS may assess the proposed changes and start collection. For a Notice of Deficiency, missing the 90‑day window means you forfeit the right to petition the Tax Court and must use other post‑assessment remedies (e.g., refund suit in a District Court is not generally an option).
  • If you miss the deadline but still respond, explain the delay, provide documentation, and ask for consideration. The IRS sometimes relents for legitimate hardships, but that outcome is not guaranteed.

Options if you can’t pay by the deadline

  • Request an installment agreement: The IRS offers short‑term or long‑term payment plans. Apply online or by phone using the contact on the notice (see IRS Installment Agreement information).
  • Offer in Compromise (OIC): If you cannot afford the tax, an OIC may settle the account for less than the full balance — but the IRS applies strict eligibility rules and documentation requirements (see IRS Offer in Compromise).
  • Request a Collections Due Process (CDP) hearing if you receive a Notice of Intent to Levy — you generally have 30 days to request a CDP hearing.

Real-world examples and timelines (typical outcomes)

  • Example 1 — CP2000 income mismatch: A client received a CP2000 with a 30‑day response window. We gathered W‑2s and payer records, responded with documentation in two weeks, and the IRS corrected the proposed changes within 60 days.

  • Example 2 — Missed deadline on a balance due notice: Another client delayed response for six weeks. The IRS placed an automated late penalty and assessed interest; we negotiated a modest installment agreement to stop further collection action.

These examples reflect common patterns, but outcomes vary by facts and timeliness.

How long the IRS will take to reply after you respond

  • Turnaround times vary. Written responses can take 6–12 weeks or longer for review; CP2000 items often take several weeks to several months to resolve, depending on complexity and IRS workload.
  • Keep copies of everything you send and follow up if you haven’t heard back within a reasonable period.

Documentation and recordkeeping (my practical rule)

Keep a single, dated folder (digital or physical) for each notice. Include:

  • The original notice and a copy of every page you send back
  • Mailing receipts or online submission confirmations
  • Notes on phone calls (date, time, representative)
  • A timeline of dates and actions

Documenting every step helped clients I work with avoid duplicate disputes and allowed quick responses to follow‑up requests.

Helpful links and additional reading

For practical site resources on FinHelp, see these related guides:

Practical tips — summary

  • Respond by the notice deadline; most routine notices give about 30 days and formal deficiency notices give 90 days.
  • Document everything and keep copies.
  • If you cannot comply by the deadline, call the IRS immediately and request an extension or discuss payment options.
  • Consider hiring a tax professional if the dispute is complex or if you face a Notice of Deficiency or a collections action.

Professional disclaimer

This article is educational and not individualized tax advice. Tax situations are fact-specific. For advice tailored to your circumstances, consult a qualified tax professional or attorney.

Authoritative sources used while preparing this entry: IRS guidance on understanding notices and collection procedures (irs.gov).