IRS Notices

CP523 Notice: Defaulted Installment Agreement and What to Do (2026)

By Angeline Balsitis, EA · Reviewed by Melissa Ly, Chief Tax Officer · Updated May 2, 2026 · Editorial Standards

Why you got a CP523 notice

You set up an installment agreement so the IRS would stop collecting while you paid your balance over time. A CP523 notice means something broke that deal, and the IRS now plans to cancel it. "Installment agreement" just means a monthly payment plan; "default" means a term of the plan wasn't met.

The most common triggers are:

• A missed or late monthly payment — even one.
• A new tax balance you owe for a later year. New debt usually breaks the existing agreement.
• An unfiled return. Your plan requires you to stay current on filing.
• Not enough withholding or estimated payments during the year, which creates that new balance.
• A returned or bounced payment from your bank.

The notice shows the tax periods involved, the amount the IRS says you owe, and the date the agreement will terminate. The IRS explains the basics on its own page, Understanding your CP523 notice.

What happens if you ignore it

The CP523 is the only warning you get before the agreement is canceled. Once that protection is gone, the IRS's automated collection machine picks up where it left off — and a defaulted-plan case can move faster than a brand-new debt. Here's the sequence:

1. CP523 — notice of intent to terminate the agreement and levy. You are here. You have 30 days.
2. Agreement terminates — after the deadline passes with no action, the plan ends and the full balance is due again.
3. Levy authority kicks in — because you already received final notice rights earlier in your case, the IRS can move to levy wages, bank accounts, and other income.
4. Wage garnishment and bank levy — your employer or bank gets the levy notice. A bank levy freezes funds for 21 days before the money is sent to the IRS; a wage levy continues paycheck after paycheck until the debt is resolved.

Interest and the monthly failure-to-pay penalty (generally 0.5% of the unpaid balance per month) keep running the entire time. In 2026, IRS staffing is stretched thin — but notices, terminations, and levies are issued by systems that don't slow down. Acting before the 30-day deadline is far easier than unwinding a levy after it lands.

First: figure out exactly why the plan defaulted

You can't fix the default until you know what caused it. Spend ten minutes confirming:

• Log into your IRS online account and check your balance, payment history, and any new tax periods. A payment may have posted late or not at all.
• Check whether you have an unfiled return. If a recent year is missing, that alone can default the agreement — even if you never missed a payment.
• Look for a new balance. If you owed for a later year, that new debt likely broke the plan. You'll need to fold it in.
• Confirm the notice is real. A genuine CP523 arrives by postal mail, never by text or email. Payments go only to the U.S. Treasury or through IRS.gov — never gift cards or payment apps. If you're unsure, our guide on how to tell if an IRS letter is real walks through the checks.

How to reinstate or fix your installment agreement

The notice makes it sound like the plan is already gone. It isn't yet — you have real options before the termination date:

• Cure the default. Make the missed payment, file the missing return, or correct whatever broke the plan. Often this alone reinstates the agreement. A reinstatement fee may apply, and it can be reduced or waived if you qualify as a low-income taxpayer.
• Modify the monthly amount. If the payment became unaffordable, call the number on the notice and ask to lower it. A revised agreement keeps the protection in place.
• Fold in a new balance. If a later year created new debt, you can usually combine the years into one updated agreement (see the IRS payment plans page). For combined balances under about $50,000, a streamlined plan over up to 72 months is often available without detailed financial disclosure.
• Request Currently Not Collectible status. If paying anything would create genuine hardship, the IRS can pause collection. The debt stays, but levies stop while your finances recover.
• Look at an Offer in Compromise. If your income and assets genuinely can't cover the debt, you may qualify to settle for less than the full balance. The IRS runs the math, not the marketing — an experienced tax professional can tell you whether you're actually a candidate before you spend anything.

How to respond to a CP523, step by step

1. Find the deadline. Read the termination date on the notice and count your 30 days. Put it on your calendar now.
2. Verify what defaulted using your IRS online account and your records (see above).
3. Cure the default if you can. Pay the missed amount at IRS.gov/payments, file the missing return, or both — before the date on the notice.
4. If you can't afford the old payment: call the number on the notice and ask to reinstate at a lower monthly amount, or to set up a new arrangement.
5. If you disagree with the termination: file an appeal through the Collection Appeals Program using Form 9423, generally within 30 days. Appealing keeps levy action on hold while it's reviewed.
6. If you owe for multiple years, have unfiled returns, or want it handled: get a professional review first. The order you fix things in — filings, then the plan, then any penalty relief — changes the outcome.

CP523 questions, answered

This guide is general information, not tax or legal advice for your specific situation. Eligibility for IRS programs depends on individual facts and circumstances; no outcome is guaranteed.

Related: see our guides on the CP504 notice of intent to levy and the LT11 final notice — or read the full order of IRS collection letters to see where you stand. You can also browse all guides.