IRS notice decoder
CP21A and CP21B: The IRS Made the Changes; One Pays You, One Bills You
The CP21 series confirms the IRS processed changes to your return. CP21B is the good letter: the changes you requested were made and a refund should arrive within 2 to 3 weeks of the notice. CP21A is the bill: the changes created a balance due, payable by the date printed on the notice, with interest accruing and a late payment penalty if you miss it.
General information, not tax or legal advice. Deadlines and dollar figures below reflect what the IRS publishes and can change; the controlling dates are the ones printed on your own notice. ClearChoiceRadar is not affiliated with the IRS or any government agency.
How an IRS correction changes your account
- Return filedAs you submitted it
- IRS changeCP12, CP21, or CP22 issued
- ResultRefund changed or balance due
- If unpaidA balance due rolls into collection notices
Which letter are you holding?
CP21B, refund version
The IRS made the changes you requested and you should receive your refund within 2 to 3 weeks of the notice. Correct your own copy of the return, and note that any interest the IRS pays you is taxable income to report next year.
CP21A, balance due version
The changes mean you owe. Pay by the date printed on the notice; interest accrues on unpaid balances and a late payment penalty applies. If you cannot pay in full, the IRS points to a payment plan, temporary collection delay, or an offer in compromise.
If you disagree with the changes
Both versions carry the same instruction: contact the IRS at the number shown on the notice. For a CP21A, the page adds that if you contact them by the payment due date, the penalty may be removable depending on your situation, which makes calling early worth something concrete.
CP21 questions
When does the CP21B refund arrive?
Within 2 to 3 weeks of the notice, per the IRS page. Interest paid with it is taxable and belongs on the next return.
What happens if I do not pay a CP21A by the date?
Interest accrues on the unpaid amount and a late payment penalty applies. Contacting the IRS by the due date can matter: the page says the penalty may be removable depending on your situation.
What is the difference between CP21A and CP22A?
Both bill you for changes to your return, and the IRS's current pages describe them almost identically. In practice the CP21 series follows changes connected to your own request or amendment, while CP22A covers changes producing a balance due; either way, the instructions and deadlines work the same.
Sources: IRS: Understanding your CP21B notice, IRS: Understanding your CP21A notice. The deadline that governs your case is the one printed on your notice.
Want help responding to a CP21?
Compare tax relief companies that handle IRS collection matters. Many offer free initial consultations; check individual providers for details.
Compare tax relief companiesWe earn compensation from companies featured on this site. This compensation may influence which companies appear and their placement. Full disclosure