You received a CP523 — the IRS is terminating your payment plan. Here's what happens next and how to stop it.

A 2025 federal case shows how CP523 notice itself becomes evidence in court

Most CP523 guides describe the notice only from the taxpayer's side — what to do when you get one. What they miss is that the CP523 also matters from the government's side: it's the document the IRS and Department of Justice have to prove they sent before they can enforce a lien in federal court, and that fight is happening in real cases right now.

A 2025 federal tax lien case in Minnesota — the CP523 as required proof of notice

In a July 2025 federal district court lawsuit in Minnesota, the government sued to reduce unpaid tax assessments to judgment and force the sale of a taxpayer's real property to satisfy federal tax liens. The taxpayers moved to dismiss, and part of their argument turned on whether the government had properly alleged that the IRS sent the required CP523 notice of intent to terminate the installment agreement before proceeding. In a November 2025 order, the court found that the government's specific allegation — that CP523 letters were sent to the taxpayers' home address by certified mail on a stated date — was sufficient to survive the motion to dismiss.

The practical lesson: keep your address current with the IRS, and if you're ever served with a lien-foreclosure lawsuit after an installment agreement default, whether and how the CP523 was actually sent is one of the first things worth checking.

What caused your installment agreement to default

The most common reasons a CP523 is issued:

• Missed payment — even one missed automatic debit or check payment can trigger a default notice
• New tax liability not included in the agreement — if you filed a return for a newer tax year and it has a balance due, that new balance often defaults the existing agreement unless it was restructured
• Unfiled return — installment agreements require you to stay current on all required filings; an unfiled return can trigger default even if you haven't missed a payment
• Missed estimated tax payments — if you're self-employed or otherwise required to make quarterly estimated payments, falling behind on those can default an existing agreement even if your installment payments themselves are current
• Failing to submit updated financial information when requested — the IRS periodically asks for a new Form 433-F or similar financial statement on larger agreements; not responding to that request is itself a default trigger, separate from missing a payment
• Levy or offset by the IRS — if the IRS applied your refund to the balance (expected and allowed) but this counted as a payment irregularity in their system

Want to see exactly what one of these looks like, section by section? The IRS publishes a full sample CP523 notice (PDF) — worth comparing line-by-line against your own.

What happens when an installment agreement is terminated

When the IRS terminates your agreement, your full remaining balance — including accrued penalties and interest — becomes immediately due. More importantly, the agreement was serving as a "stay" on active collection. Once terminated, the IRS's ability to levy wages and bank accounts is restored.

There's also a real, quantified cost to losing the agreement: the IRS's failure-to-pay penalty runs at a reduced 0.25% per month while an approved installment agreement is in effect for that tax. Once it's terminated, that protection disappears — and if a formal Notice of Intent to Levy isn't satisfied within 10 days, the penalty rate can jump to 1% per month. On a large balance, that difference compounds fast.

Separately, the IRS can also file a Notice of Federal Tax Lien (NFTL) at the same time — and you have an independent right to appeal a proposed lien filing through the same Collection Appeals Program described below, distinct from appealing the agreement termination itself.

A CP523 default can also put your passport at risk

The IRS's own CP523 explainer flags this directly, and almost no third-party guide does: losing your installment agreement can expose you to passport denial or revocation under IRC § 7345 (the FAST Act passport-certification rule) — something that only matters for larger balances, but matters enormously when it applies.

Here's the mechanism. The IRS can certify you to the State Department as having "seriously delinquent tax debt" if your unpaid balance (tax, penalties, and interest combined) exceeds $66,000 for 2026 (the threshold adjusts for inflation each year) and the IRS has already filed a Notice of Federal Tax Lien with exhausted appeal rights, or issued a levy. Once certified, the State Department will not issue or renew your passport, and can revoke one you already hold.

Critically, being in a current, IRS-approved installment agreement is one of the statutory exclusions from certification under IRC § 7345(b)(2) — it doesn't matter how large your balance is while the agreement is being paid on time. That protection is exactly what a CP523 default takes away. If your balance is above the threshold and a lien or levy is already on file, defaulting the agreement can make you newly eligible for certification — and the notice you'd get for that is a separate one, CP508C.

How to respond to a CP523

1. Identify what caused the default. Check your IRS Online Account (irs.gov/account) to see your payment history and any new balances. This tells you whether the default was a missed payment, a new tax liability, or an unfiled return.
2. Cure the default if possible. If you missed a payment, making that payment immediately (and catching up any missed months) can sometimes reinstate the agreement — particularly if this is your first default and you call the IRS's installment agreement line to request reinstatement. Pay directly at the official IRS payments page (irs.gov/payments) rather than any third-party site — it's free, gives instant confirmation, and lets you schedule or modify the payment before it processes.
3. File any missing returns. If an unfiled return triggered the default, file it immediately. You may be able to add the new balance to a restructured agreement.
4. Request a new installment agreement. If the agreement can't be reinstated, you can apply for a new one. The terms may be different — particularly if your balance has grown or your financial situation has changed.
5. Consider whether an OIC is now more appropriate. If your financial situation has significantly worsened since the original agreement was set up, an Offer in Compromise may now make more sense than reinstating a payment plan you can no longer sustain — and with current IRS staffing delays, the 24-month deemed-acceptance rule has real teeth.
6. If you disagree with the default itself, don't just call — appeal it. Calling and asking nicely isn't the same as exercising your formal appeal rights under Form 9423. See the appeal option below if you think the IRS got it wrong.
7. If your balance is near $66,000, check your passport exposure. See the section above — this is the consequence people miss until it's inconvenient.

Reinstating, restructuring, appealing, or replacing your agreement

Reinstatement

If this is your first default and you catch up the missed payment(s) quickly, you can often call the IRS and request reinstatement. The IRS frequently grants this as a one-time courtesy, particularly for agreements that had been in good standing. You may need to provide updated financial information.

Reinstating or restructuring a defaulted agreement carries a $89 user fee under 26 CFR § 300.1 — reduced to $43 if you qualify as a low-income taxpayer (generally, adjusted gross income at or below 250% of the federal poverty guidelines). This fee is rarely stated precisely elsewhere; budget for it when you call to reinstate.

Restructuring

If a new tax balance pushed you into default, restructuring the agreement to include the new balance is the most common path. Your monthly payment will likely increase to cover the new balance within the remaining statute period, but the structure of the agreement remains.

Formally appealing the termination (Form 9423 / CAP)

Calling to ask for reinstatement and formally appealing are two different things, and most guides only describe the first. If you genuinely disagree that you defaulted — for example, you believe a payment posted late through no fault of your own, or a balance was already resolved before the notice went out — you have the right to challenge the termination through the Collection Appeals Program (CAP) using Form 9423, Collection Appeal Request.

• Deadline: generally 30 days from the date of the notice terminating (or rejecting or modifying) your installment agreement.
• Process: call the IRS number on your notice first and ask for a conference with the Collection manager if you disagree — for installment agreement actions, this informal step is recommended but not always required before filing Form 9423.
• Effect: filing a CAP appeal generally pauses further collection action while it's under review, which reinstatement-by-phone alone doesn't guarantee.
• Tradeoff: a CAP decision is typically final and binding, with no Tax Court review — it's meant to be fast, not to relitigate how much tax you owe.

The IRS's own reference materials for this (Publication 1660, Collection Appeal Rights) are listed on the official CP523 page but rarely surface in third-party explainers — worth reading before you call if you plan to push back rather than simply ask for reinstatement.

New agreement

If the original agreement is terminated before you can act, you apply for a new installment agreement from scratch. Depending on your total balance, this can be done online (under $50,000) or requires a Form 9465 with financial information.

Where other CP523 guides fall short — and how we keep this one current

Before trusting any CP523 guide — including this one — it's worth checking when it was actually last updated and against what. A few honest observations about what's currently ranking for "CP523":

• The reinstatement fee is almost never stated as a number. Guides say "you may incur a reinstatement fee" without giving the figure — it's $89, or $43 for low-income taxpayers, under 26 CFR § 300.1.
• Not all four default triggers are consistently covered. Missed payments and new tax balances are universally mentioned; missed estimated tax payments and a failure to submit updated financial information when the IRS requests it are covered far less often.
• No case law or actual litigation is cited anywhere in current CP523 guides — the November 2025 federal case above, where CP523 notice sufficiency was directly litigated, doesn't appear in any competing explainer we found.
• Passport risk is almost never connected to a CP523 specifically. The IRS's own CP523 page mentions passport denial and revocation directly, but most third-party guides discuss passport certification (if at all) only on separate, generic "back taxes and passports" pages — never tied to the installment-agreement-default scenario where it's most likely to blindside someone.
• Formal appeal rights (Form 9423 / CAP) are conflated with "just call and ask." Nearly every guide tells you to call the IRS if you disagree with the termination, but almost none distinguish that from your actual right to a Collection Appeals Program review — a meaningful difference if the IRS won't budge on the phone.
• Almost every guide describes the LT11 as a separate future notice. The CP523 itself is your legal Notice of Intent to Levy under IRC § 6331(d) — it says so on the notice. Waiting for a separate LT11 before taking this seriously is a mistake we haven't seen corrected anywhere else.
• The "I got two CP523 letters" confusion is real and unaddressed. It's common enough to have its own dedicated threads and videos, but the actual explanation — one notice per tax period, one payment to cure all of them — rarely appears in writing.
• Authorship is often generic or anonymous. Several ranking CP523 pages carry no named, credentialed author at all.

Frequently asked questions about CP523