IRS NOTICE REFERENCE
Understanding your CP21B notice
We sent you this notice because we made the changes you requested to your tax return for the tax year specified on your notice. You should receive your refund within 2-3 weeks of your notice.
General information only. Not legal or tax advice.
Notice details
- Notice code
- CP21B
- Category
- Refund and adjustment
- Severity tier
- Tier 1 — Routine. Informational or administrative notice; no response typically required.
- Governing law
- §6213(b); §6402 (Internal Revenue Code sections)
- Source
- IRS.gov — Understanding Your IRS Notice
What this notice is
We sent you this notice because we made the changes you requested to your tax return for the tax year specified on your notice. You should receive your refund within 2-3 weeks of your notice.
Source: IRS.gov. Reproduced for reference. General information — not legal or tax advice.
What the IRS says to do
If you disagree with the changes we made, contact us at the number shown in the “What you need to know” section of your notice. Correct the copy of your tax return that you kept for your records. Be sure to report any interest we paid you on your tax return for this year. For more information on reporting interest income, see About Form 1099-INT, Interest Income .
This is the IRS’s own guidance reproduced from the IRS notice page. It describes the IRS’s process — it is not legal or tax advice from TaxRiskOS.
Official IRS reference
Read the official notice page on IRS.gov: https://www.irs.gov/individuals/understanding-your-cp21b-notice
Related tools
TaxRiskOS is workflow software for practitioners — it captures the notice, computes the deadline, surfaces the escalation tier, and builds a document checklist. It documents process; it does not give advice or draft responses.
Check this notice’s deadline (free tool)