- What it means
- Installment agreement reminder for specific account types
- Respond within
- The date printed on the notice
- When to get help
- If a CP523 arrives and you cannot cure the default within 30 days, use the hearing right to propose a revised plan rather than letting it terminate.
The first move
Read whether the letter confirms, changes, or threatens the plan. A missed payment defaults the agreement and restarts collection; a CP523 is the warning.
What letters in this family have in common
An installment agreement is a contract. The IRS confirms it (CP89 annual statement, CP521 monthly reminder), tells you when it changes the terms, and tells you when you are breaking it. The CP523 is the one that matters: it says the agreement is in default and will terminate in 30 days unless you catch up, and it carries the intent to levy and hearing rights.
Common causes of default are a missed payment, a new balance from a later year that was not added to the plan, or a return filed late while the plan was active. The fix for a missed payment is to make it. The fix for a new balance is to call and have it added, or to reinstate the agreement, which carries a fee.
While a plan is current, the failure-to-pay penalty is halved and the notices stop. That is worth keeping.
What to gather
- The agreement confirmation and the monthly amount
- Your payment history for the plan (bank statements, IRS account transcript)
- The CP523 if you received one, with its date
- Any new balance due notice for a later year
How to write back
- Payment plan request cover letter: A cover letter to accompany Form 9465 or an online payment plan confirmation, stating the balance, the proposed monthly amount, and the first payment date.
Closest built pages
- CP521: Installment payment due
- CP523: Installment agreement in default
- CP89: Annual installment agreement statement
- CP522: Financial information needed for your payment plan
- CP166: Direct debit installment payment failed
- CP621: Spanish-language version of CP521
Before you send anything
This is general information, not tax advice. Situations differ. Check with your tax advisor before you send anything. Nothing on this page creates a client relationship.