Quick answer: IRS letters follow a predictable escalation: bills (CP14), reminders (CP501, CP503), levy warnings (CP504), and final notices with hearing rights (LT11, Letter 1058). The code in the top corner tells you exactly where you are in that sequence — and how much time you have. Or use our instant Notice Decoder.
Urgent — a legal clock is running
LT11 / Letter 1058 — Final Notice of Intent to Levy. The IRS can seize wages and bank accounts after 30 days; a timely hearing request pauses it. Full guidance →
CP504 — Notice of Intent to Levy. The IRS can take your state refund now and is one step from final levy powers. Full guidance →
CP90 / CP297 — Final Notice of Intent to Levy. Same 30-day hearing right as LT11 — use it.
CP91 — Intent to Levy Social Security. Up to 15% of benefits can be taken; hardship programs often stop it.
CP3219A — Statutory Notice of Deficiency. 90 days to petition Tax Court. The deadline cannot be extended.
CP523 — Installment Agreement Default. Your plan is about to be terminated; reinstatement is usually possible if you act fast.
Letter 3172 — Federal Tax Lien Filed. A lien now attaches to your property, with a 30-day hearing right.
Time-sensitive — respond before it escalates
CP2000 — Proposed Changes. Reported income doesn’t match your return; the proposal is often too high. Full guidance →
CP14 — Balance Due. The first bill. Penalties and interest are accruing daily. Full guidance →
CP501 / CP503 — Reminders. The escalation ladder between the first bill and levy warnings.
CP11 — Math Error, Balance Due. The IRS corrected your return; you generally have 60 days to dispute. Full guidance →
CP21 / CP22 — Account Changes. Adjustments created a balance; verify against your records before paying.
CP59 — Unfiled Return. Missing returns block every resolution program — filing usually beats the IRS’s substitute figures.
CP161 — Business Balance Due. Business and payroll tax debt escalates faster than personal — and can become personal liability.
Informational — review calmly
CP12 — Math Error, Refund Changed. Your refund was adjusted; dispute within the stated window if you disagree.
CP49 — Refund Applied to Debt. Your refund went to an old balance — a sign the underlying debt needs resolving.
CP71C — Annual Reminder. A yearly statement of old debt; a good prompt to finally resolve it.
Don’t see your letter? Read it to us.
Free 15-minute call. We’ll tell you what it is, how urgent it is, and what to do — in plain English.