IRS CP501: what it means and what to do
This is a reminder that you still owe a balance on one of your tax accounts. The IRS hasn't received your payment or a response to an earlier notice. This summary is drawn from the IRS page for the CP501, last checked on October 13, 2026.
Why you received a CP501
- The IRS hasn't received payment or a response to an earlier notice asking you to pay this balance
What to do
- Read the notice for the amount owed, due date, and payment options
- Pay by the due date shown on the notice
- If you can't pay in full, apply for a payment plan
- If you disagree, call the toll-free number on the notice
Deadline: Pay by the due date shown on the notice
If you disagree, or do not respond
Call the toll-free number on your notice right away and have supporting documents ready, such as cancelled checks or an amended return.
The IRS can file a notice of federal tax lien, a public notice to creditors that the government has a right to your assets. Interest keeps accruing and additional penalties may apply.
Get your records together first
Most notices come down to matching what the IRS has on file against your own records. Before you reply, pull the return the notice refers to, the bank statements and income forms for that year, and any payment confirmations. If your books are reconciled to the bank, that comparison takes minutes instead of days.
Source and verification
IRS: Understanding your CP501 notice →
Last verified against that page on October 13, 2026. This is general information, not advice for your situation. The notice itself is the authority on your amounts and dates. Talk to a CPA or enrolled agent if the amounts are large or you are unsure.
Related
- All IRS notices explained
- IRS CP2000 — The IRS is proposing changes to your tax return because income or payment information it received from third parties does not match what you reported.
- IRS CP14 — The IRS says you owe money on unpaid taxes.
- IRS CP503 — This is your second reminder that you have an unpaid balance on one of your tax accounts, because the IRS hasn't received your payment or a response to earlier notices.
- IRS CP504 — This is a Notice of Intent to Levy under Internal Revenue Code section 6331(d) and a final reminder that the IRS may levy your wages, bank accounts, or state tax refund for an unpaid balance.
- IRS LT11 — The IRS has not received payment for overdue taxes and intends to seize your property or rights to property.
- IRS CP90 — The IRS intends to levy (seize) certain assets to collect unpaid taxes.
- Find an accountant — for help responding.
Frequently asked questions
What is an IRS CP501 notice?
This is a reminder that you still owe a balance on one of your tax accounts. The IRS hasn't received your payment or a response to an earlier notice.
How long do I have to respond to a CP501?
Pay by the due date shown on the notice Check the date printed on your own notice, which is the one that applies to you.
What happens if I ignore a CP501?
The IRS can file a notice of federal tax lien, a public notice to creditors that the government has a right to your assets. Interest keeps accruing and additional penalties may apply.
What if I disagree with the CP501?
Call the toll-free number on your notice right away and have supporting documents ready, such as cancelled checks or an amended return.
What do I have to do?
Pay by the due date, or request a payment plan if you can't pay in full.
Am I charged interest?
Yes, interest applies to underpayments until paid in full. The bill summary section of the notice shows the total.
Will I get a penalty if I can't pay in full?
Yes, a failure-to-pay penalty applies. Contacting the IRS by the due date may allow the penalty to be removed.
What if I need to correct my return?
File Form 1040-X.
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Authoritative sources
US tax rules change every filing season. Always verify the current position with the official sources below before filing.
- IRS — irs.govInternal Revenue Service. Forms, publications, due dates, and current-year thresholds for federal income tax, payroll tax, and 1099 reporting.
- IRS — Forms & InstructionsCanonical PDF forms (W-4, W-9, 1099-NEC, 1040-ES, 941, 940, W-2, W-3) with current-year instructions.
- SSA — Business Services OnlineSocial Security Administration portal for W-2 / W-3 e-filing, EIN verification, and AccuWage validation.
- Streamlined Sales Tax — streamlinedsalestax.orgMulti-state Streamlined Sales and Use Tax Agreement (SSUTA) — registration in 24 SST member states with one application.
- Tax Foundation — Sales Tax & NexusIndependent state-by-state research on sales tax rates, economic nexus thresholds, and franchise / margin tax structures.
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