Quick overview

A 30‑Day Notice from the IRS is a time‑sensitive letter that requires action within 30 calendar days. Depending on the notice type, the 30‑day clock protects your right to challenge an IRS decision (for example, via a Collection Due Process hearing) or to provide documentation that cancels a proposed adjustment. In practice I’ve seen prompt, well‑documented responses reverse or reduce proposed liabilities in the majority of routine cases.

Types of 30‑Day Notices (short summary)

  • Adjustment notices (commonly issued as a “notice of proposed adjustment”, e.g., CP2000) — these propose changes to your tax return and typically give 30 days to respond with supporting documents or an agreement.
  • Collection‑related final notices — certain final notices of intent to levy or to file a Notice of Federal Tax Lien include a 30‑day right to request a Collection Due Process (CDP) hearing before the IRS proceeds.

Both kinds of 30‑day letters require timely action, but the remedies differ: provide documents and explanations for adjustment letters; request a CDP hearing or propose collection alternatives for levy/lien letters. For more on CP2000‑style adjustment letters, see our guide to Steps to Take When You Receive a Notice of Proposed Adjustment (CP2000).

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Step-by-step response checklist (what to do in the first 48 hours)

  1. Read the notice in full and note the date on the letter. The 30‑day deadline begins on the date shown on the notice.
  2. Identify the notice type and the IRS contact or address for responses. The letter will say whether it is a “proposed adjustment” notice (answer with documentation) or a “final notice” that carries CDP rights.
  3. Don’t ignore the notice. Mark a calendar reminder 5 business days before the 30‑day deadline so you can finalize your response.
  4. Gather documentation immediately: tax returns, W‑2s, 1099s, bank records, receipts, canceled checks, professional invoices, and any correspondence that proves your position.
  5. Draft a concise cover letter: reference the notice number, year in question, and state clearly whether you agree, partially agree, or disagree. Attach supporting documents and a page‑by‑page index.
  6. Mail or upload your response per the instructions on the notice. Use certified mail with return receipt if sending by post; keep copies of everything.

In my practice, responses that follow steps 4–6 and include a short, evidence‑focused explanation get reviewed faster and are more likely to resolve without escalation.

If you agree with the IRS

  • Pay or arrange payment promptly. If you can’t pay in full, immediately contact Collections to request an installment agreement or an Offer in Compromise (OIC) if eligible. The IRS provides online payment tools and phone options; document every conversation and confirmation number.
  • If the notice is an adjustment and you accept it, sign and return the statement the IRS provides (if included).

Authoritative sources: IRS payment options and online tools (IRS.gov).

If you disagree: documentation, appeals, and hearings

  • Provide clear documentary evidence that addresses each IRS adjustment point (for income mismatches, supply the Forms W‑2/1099 and the return line references showing the reporting).
  • If the notice is a final collection notice (for example, Final Notice of Intent to Levy), you have 30 days to request a Collection Due Process (CDP) hearing with the IRS Office of Appeals. Requesting a CDP hearing within 30 days preserves important rights and delays levy or lien activity. (See IRS: Collection Due Process and Equivalent Hearing Rights.)
  • For proposed adjustments you cannot resolve directly with the agent, you may appeal to the IRS Office of Appeals. Appeals deadlines and procedures vary; in some cases a 90‑day statutory notice of deficiency or other time limits apply.

Citations: IRS — Collection Due Process information and appeals procedures (IRS.gov).

Common documentation checklist

  • Relevant federal and state tax returns for the years in question
  • W‑2, 1099, and K‑1 statements
  • Bank statements and cancelled checks
  • Receipts, invoices, mileage logs, and proof of business use
  • Contracts, settlement statements, or closing documents for property transactions
  • A concise, page‑numbered index linking each document to the IRS’s adjustment line items

Tip from practice: organize documentation by issue (income, deductions, credits) rather than by date — it makes the IRS reviewer’s job easier and speeds resolution.

Timelines and what happens if you don’t respond

  • Respond within 30 calendar days. If you miss that window:
  • For adjustment notices, the IRS may assess the proposed change, add interest, and begin collection activity.
  • For collection final notices, missing the 30‑day deadline can mean you lose the automatic right to a CDP hearing; the IRS may proceed with levy or file a Notice of Federal Tax Lien.
  • You can still challenge an action later, but the process is more complex and often requires a post‑levy collection appeal, Tax Court petition (where applicable), or litigation — all of which are slower and costlier.

For a deeper discussion on deadlines and extensions, see our article on timelines for responding to IRS notices.

Common mistakes taxpayers make

  • Replying with vague statements or unsupported claims rather than hard documents.
  • Waiting to collect evidence until close to the deadline.
  • Sending documentation to the wrong IRS address or failing to include the notice number.
  • Assuming a phone call alone resolves the matter — always get written confirmations.

Sample timelines for a typical CP2000‑style 30‑day notice

  • Day 0: Notice date — 30‑day clock starts.
  • Days 1–7: Gather documents; call the number on the notice only to confirm receipt and the correct mailing/upload address.
  • Days 7–21: Send a complete response with index and copies of evidence (keep originals). If mailing, use certified mail.
  • Day 30 (or earlier): If the IRS requests additional information, provide it immediately; if unresolved, consider filing an appeal.

This practical timeline reduces the risk of missed steps and often resolves simple mistakes within 60–90 days.

When to call a tax professional or consider formal representation

  • Complex adjustments (large business items, IRC §6662 penalty issues, or multi‑year errors).
  • When the IRS proposes a high tax liability or penalties you dispute.
  • If levy, lien, or enforced collection action is imminent.

In my 15 years advising clients I find the right professional can often negotiate payment plans, remove incorrect penalty assessments, or escalate cases to Appeals with a strong chance of favorable settlement.

What to expect after you respond

  • The IRS may accept your documentation and close the case, propose a partial settlement, or request further proof.
  • If the IRS proceeds despite your response, the letter will explain next steps and appeal rights. Keep copies and track dates — appeals often hinge on strict deadlines.

Bottom line: act quickly, document thoroughly, protect your rights

A 30‑Day Notice is urgent but manageable. The key actions are: read the notice, gather and index evidence, respond in writing per the notice instructions, and if needed, request the appropriate hearing or appeal within the stated timeframe. If you’re unsure, seek a qualified tax professional promptly.

Sources and further reading

Professional disclaimer: This article is educational and does not constitute tax, legal, or financial advice. For guidance tailored to your facts, consult a licensed CPA, enrolled agent, or tax attorney.