CP523· Collection / payment due
CP523 — Installment agreement default
- Category
- Collection
- Urgency
- Time-sensitive
- Response window
- 30 days
- Key form
- Form 9465
A short, often fixed window — act promptly.
Why the IRS sent this
Default on an active installment agreement (missed payment, new balance assessed, or other agreement term violated).
Response window · stated on irs.gov
30 daysMake the past-due payment before the termination date stated on the notice, or contact the IRS to seek reinstatement of the agreement.
What to do
Required action
Make the past-due payment before the termination date stated on the notice, or contact the IRS to seek reinstatement of the agreement.
Key form: Form 9465 — verify the current revision on irs.gov/forms-pubs before filing.
Appeal path
Independent Office of Appeals
The Independent Office of Appeals is referenced; Publication 1660 (Collection Appeal Rights) is the procedural source.
Pub 5Notes from the primary source
30-day window is stated on the IRS detail page.
Go deeper
Educational pillars for this notice
Calm-corrective
Only the IRS can resolve your notice
We are not a CPA firm, not a law firm, not an Enrolled Agent firm, and not affiliated with the IRS. We don't accept payments on your behalf, settle your debt, or call the IRS for you. What we do: explain what your notice means, point you to the right IRS form, cite the statute that authorizes the action, and surface the appeal path. Then you call the number on the notice, file the form, or hire a licensed professional.
Related notices
Likely next or sibling codes
- CP504Notice of intent to levy: if the balance is not paid immediately, the IRS may seize state tax…
- LT11Final Notice of Intent to Levy and notification of your right to a Collection Due Process (CDP)…
- CP14First IRS bill telling you a balance is owed for a specific tax year. The notice states the…
- CP501First reminder that a balance is still owed after a previous balance-due notice went unanswered.
- CP503Second reminder that a balance is still owed and prior notices have gone unanswered.
- CP90Notice of intent to levy assets and notification of the right to a Collection Due Process (CDP)…
Source
Verified against the official IRS detail page on irs.gov/individuals/understanding-your-cp523-notice. Always re-verify against the IRS page before acting.