IRS NOTICE
CP523 — Notice of intent to terminate installment agreement
The IRS's notice that an existing installment agreement is at risk of default, typically due to a missed payment, a new balance, or an unfiled return. The taxpayer has a window to reinstate before the agreement terminates and the full balance becomes due.
General information only. Not legal or tax advice.
Typical response window
Typically about 30 days. The reinstatement window printed on your notice governs. If the agreement terminates, the full balance and accrued interest become immediately due.
What the first hour looks like
Identify the default reason, pull the agreement and payment history, assess whether reinstatement is possible, and route for a resolution decision before the window closes.
Starter document checklist
- The CP523 notice
- The existing installment agreement (Form 433-D or acceptance letter)
- Payment history for the agreement — all scheduled and actual payments
- The tax period that triggered the default (missed payment, new balance, or unfiled return)
- IRS account transcript
- Documentation of any payments already made to cure the default
Do the whole first hour in one place
TaxRiskOS captures the notice, computes the deadline, builds the checklist, flags whether it needs partner or counsel review, and produces a clean handoff packet — the first hour, made repeatable. It documents process, not advice.