What we cover
Choose the letter
you have in hand.
Each page is built from official IRS material. The code tells us the category; your paper tells us the exact date and facts.
01CP14Balance due noticeBalance due02CP501First reminderBalance due03CP503Second reminderBalance due04CP504Urgent balance-due noticeCollection action05LT11/1058Final notice before levyLevy and hearing rights06CP90Final notice of intent to levyLevy and hearing rights07CP523Installment agreement defaultPayment plan08CP2000Proposed income mismatchProposed adjustment093172Notice of federal tax lienLien record103219Notice of deficiencyTax Court deadline11525Examination reportExamination12CP11Return corrected, balance dueReturn change13CP12Return corrected, refund changedReturn change1412CMore information needed to process returnReturn processing15CP23Estimated tax difference, balance dueReturn change16CP24Estimated tax difference, credit dueReturn change17CP49Refund applied to a tax debtRefund offset18CP59Unfiled return noticeMissing return19CP88Refund held for unfiled returnsMissing return20CP05Return under reviewReturn review21CP75Credit audit, refund heldExamination22LT16Unpaid tax or missing returns warningCollection action23CP71CAnnual balance reminderBalance due244883CIdentity verification by phoneIdentity verification255071CIdentity verification noticeIdentity verification264464CReturn under review letterReturn review275747CIn-person identity verificationIdentity verification281153Proposed trust fund penaltyTrust Fund Recovery Penalty