October 18, 2026 · Daniel Ali

IRS Code 424: Examination Request — Meaning, Timeline & What To Do

IRS Code 424 means examination request — your return was referred to the Examination division, not yet a full audit

Direct answer: IRS Code 424 means your tax return was referred to the Examination or Appeals Division — an examination request. It does not by itself mean a full audit is underway. It means the IRS set your return aside for examination after initial review, generated opening-inventory information for the examining unit, and may or may not follow up with a letter. If no letter arrives and no further codes post, the referral may simply end there.

What Code 424 Means

Code 424 is one of the least explained codes on an IRS account transcript, partly because it is less common than its neighbours and partly because most guides lump it together with Code 420. The IRS’s own code book, Document 6209, defines Transaction Code 424 as the “Examination Request Indicator” — a return referred to the Examination or Appeals Division, which generates examination opening-inventory information. In plain language: your return was pulled out of the normal processing stream and handed to the unit that handles examinations.

That sounds alarming, but the referral itself is an administrative step, not a verdict. The IRS selects many returns for examination and audits only a fraction of those selected. A 424 can post and then nothing further happens. It can also be followed by a letter asking for documents, by a freeze, or by a reversal (Code 425, which reverses a 424). What matters is what comes after the 424, not the 424 alone.

One important distinction: 424 does not freeze your refund by itself. If your refund is also held, that is because a separate freeze code — usually IRS Code 810: Refund Freeze — posted alongside it. Many taxpayers see 424 and 810 together and assume the 424 caused the freeze. The two codes serve different jobs: 424 is the referral, 810 is the freeze.

424 vs 420 vs 421

Codes 420, 424, and 421 form a small family, and mixing them up is the most common source of confusion about 424. Here is how they differ:

Code	Meaning	What it tells you
420	Examination indicator	Your return was flagged for possible examination
424	Examination request	Your return was actually referred to the Examination or Appeals Division
421	Examination closed	The examination was closed (check the notice for the outcome)
425	424 reversed	The 424 referral was reversed

Think of it as a pipeline. Code 420 is the flag: the system noticed something worth a closer look. Code 424 is the handoff: the return moves to the examining unit and opening-inventory information is created. Code 421 is the close: the examination ended. A return can carry 420 and then 424, or 424 can appear on its own. Either way, 424 is a step further along than 420 — the referral has actually happened.

For the full story on the first step, read IRS Code 420: Examination Indicator — Audit or Just Review?. If your transcript shows 421, the examination is closed, but you still need the notice or the adjustment codes (usually in the 29X/30X range) to know the outcome — closed does not automatically mean “no change.”

424 With 810 / 811 (Freeze and Release)

The combination taxpayers ask about most is 424 with 810. Here is how to read it:

424 + 810: Your return was referred for examination and your refund is frozen while the examination is open. The freeze stays until the examining unit releases it.
424 + 810 → 811: Code 811 reverses the freeze. The refund freeze is lifted, but the 424 referral may still be open — 811 releases money, not the examination.
424 → 425: The referral was reversed. If 810 also posted, watch for 811 to release the freeze.

If you see 424 with 810 and no 811 for weeks, that is the normal shape of an open examination, not a sign that something went wrong with your account. The freeze exists so the IRS does not pay out a refund it may later need to adjust. For the freeze side of this pair, read IRS Code 810: Refund Freeze vs Code 570 & How It Clears.

What Letter to Expect (CP75 / CP75A, or None)

A 424 does not always produce a letter. Sometimes the examining unit reviews the return, finds nothing that needs taxpayer input, and the case closes quietly. When a letter does come, the most common ones connected to a 424 referral are in the CP75 family:

CP75: The IRS is auditing your return and needs documentation to verify the Earned Income Credit (EIC) you claimed. The IRS holds the EIC and/or Additional Child Tax Credit portions of your refund until the examination is complete. The notice tells you exactly what to send and the date to send it by.
CP75A: Similar to CP75, but it covers additional items beyond the EIC — for example, filing status, dependent exemptions, or other credits. The response process works the same way: send what the notice asks for, by the date shown on it.
Other notices: Depending on what the examination covers, you could instead receive a CP2000 (proposed adjustment from an income mismatch), a CP05 (return under review), or a notice specific to the issue being examined. The notice number matters more than the 424 itself.

Two rules for any letter that arrives. First, respond to the address and by the date shown on the notice itself — not to a phone number from a search result, and not to a deadline someone on a forum quoted. Second, send copies, never originals. The Taxpayer Advocate Service gives the same advice for CP75-series notices: read the letter, follow its instructions, and keep copies of everything you submit.

If no letter arrives within a few weeks of the 424 posting, that is not unusual either. Check your IRS Online Account for digital copies of notices, and keep watching your transcript for follow-up codes (421, 425, 811, or adjustment codes).

What to Gather — and What NOT to Send Yet

If your 424 is followed by a notice, the notice will list exactly what the IRS wants. Until then, do not send anything. Unsolicited documents can slow a case down, because they have to be matched to a case that may not have a document request open yet.

That said, it costs nothing to get your records in order while you wait. Depending on what the examination might cover, pull together:

Your filed return for the year in question, plus any schedules (especially Schedule C, EIC worksheets, or child-related credits).
Income records: W-2s, 1099s, and any records behind income the IRS may question. If there is an income mismatch, a Code 290 adjustment may follow — matching your records to the notice is how you check it.
Credit documentation: For EIC or Additional Child Tax Credit reviews, school, medical, or residency records showing a qualifying child lived with you, plus birth certificates or relationship records if the notice asks for them.
Prior correspondence: Any earlier notices for the same tax year, including a 971 notice-issued line and the notice number beside it.

What not to do: do not call the IRS demanding an immediate answer the week the 424 posts — the examining unit may not have opened the case yet, and there may be nothing to discuss. Do not pay anyone who contacts you claiming to be from the IRS and demanding immediate payment; the IRS initiates examinations by mail, not by threatening phone calls. And do not file an amended return to “fix” something while an examination is open unless the IRS or a tax professional tells you to — an amended return during an open exam can complicate the case. (For context on how amended returns post, see IRS Code 977: Amended Return Filed.)

How Long 424 Can Last

There is no fixed IRS timeline for how long a 424 referral lasts, and any source that gives you a single number is guessing. Forum anecdotes range from a few weeks to several months, and both can be true for different cases — a straightforward document review closes faster than a complex examination, and some referrals close with no taxpayer contact at all.

What governs the timeline is the examination itself: whether a letter was issued, whether you responded by the date shown, and whether the examining unit needs more information. Your transcript and your notices are the only reliable progress indicators. If a 424 has sat on your transcript for months with no letter and no follow-up codes, that is a legitimate reason to call the IRS or contact the Taxpayer Advocate Service — but give it time first, because examinations are not processed on the same clock as ordinary refunds.

A useful mental model: a 424 is not a countdown. It is a status. It stays until the examining unit acts (letter, adjustment, or closure) or reverses it (425).

What Comes After 424 Clears

A 424 clears in one of three ways, and each has a different next step:

421 posts (examination closed). Read the outcome from the notice or the adjustment codes. If adjustment codes in the 29X/30X range post, match them to the notice — an amount may be due, or a refund may follow. If nothing changes, the return was accepted as filed.
425 posts (424 reversed). The referral was undone. Processing usually resumes, and if a freeze was in place, watch for 811 to release it, then 846 (refund issued) for the refund itself.
The case resolves through a notice response. You sent documents, the IRS accepted them, and the examination closes — again, 421 and any adjustment codes tell the story.

In every path, the sequence after 424 matters more than the 424 itself. If a refund is due, 846 is the code that means it was issued — no earlier code guarantees a refund. If an adjustment is due, the notice and the 29X/30X codes tell you the amount and the deadline to respond or pay. And if a hold was part of the story, the 571 hold-released code may appear on its own track — the two processes can run in parallel.

For the complete map of transcript codes and how they fit together, start with the IRS Transcript Codes: Complete List and Meanings guide.

FAQ

Does IRS Code 424 mean I am being audited?

Not necessarily. Code 424 means your return was referred to the Examination or Appeals Division — an examination request. The IRS selects many returns for examination and audits only a fraction of those selected. You may receive a letter asking for documents (a correspondence examination), or the referral may close with no further action. A 424 alone does not prove a full audit is underway.

What is the difference between Code 420 and Code 424?

Code 420 is the examination indicator — your return was flagged for possible examination. Code 424 is the examination request — the return was actually referred to the Examination or Appeals Division and opening-inventory information was generated. Think of 420 as the flag and 424 as the handoff. A return can show 420, then 424, or 424 on its own.

Will I get a letter after Code 424?

Maybe. Some 424 referrals produce a letter (often in the CP75 family for credit examinations, or a CP2000 for income mismatches), and some close without any letter. If a letter comes, respond to the address and by the date shown on the notice itself, and send copies, never originals. Check your IRS Online Account for digital copies of notices.

Does Code 424 freeze my refund?

No — not by itself. A refund freeze comes from a separate code, usually Code 810. If you see 424 and 810 together, the 810 is what holds the refund while the examination is open. Code 811 later releases the freeze. If you see 424 without 810, your refund is not frozen by the 424.

How long does Code 424 stay on my transcript?

There is no fixed IRS timeline. Timing depends on the examination: whether a letter was issued, whether you responded by the date shown, and whether the examining unit needs more information. Anecdotes range from weeks to months. If a 424 sits for months with no letter and no follow-up codes, calling the IRS or the Taxpayer Advocate Service is reasonable.

What comes after Code 424?

Three paths: 421 (examination closed — read the outcome from the notice or adjustment codes), 425 (424 reversed — processing resumes), or resolution through a notice response (you sent documents and the examination closed). In every path, watch for 811 if a freeze was in place, and 846 if a refund follows.

Related Guides

*Disclaimer: This article is general information only, not tax advice. Your transcript, notices, and the IRS’s records govern your case. If you face an examination, consider consulting a qualified tax professional or contacting the Taxpayer Advocate Service.*

Sources: IRS Document 6209, Transaction Code 424 (Examination Request Indicator) · IRS — Understanding Your CP75 Notice