CP501
read it properlyReminder — balance due
A reminder that you still owe a balance.
No day count is published. The due date shown on the notice governs.
If it passes. Interest accrues, penalties may be added, and the IRS can file a Notice of Federal Tax Lien.
Why you got it
The CP14 went unpaid.
What rights it carries
You can appeal through the Collection Appeals Program. Note what that is not: CAP has no judicial review, and no Collection Due Process right attaches at this stage.
Do you have to respond?
No formal response required.
The mistake people make
Assuming that because nothing has been seized, nothing is happening. Interest and the failure-to-pay penalty compound the whole way through, and a lien can be filed here.
If crypto is why this arrived, the number on it is probably wrong.
Your exchange reports what you sold for and leaves the cost box blank, so any figure the IRS computes from it treats every coin as though it cost you nothing. Rebuild the basis from your own transaction history — free — and see the real number before the deadline above runs out.
Notices that arrive around this one
CP503 — The IRS has not heard from you and the balance is still unpaid. CP504 — A real levy warning — but a narrow one. On its own this notice supports a levy on your state income tax refund and nothing else. CP90 — The final levy notice — and the last document in the whole collection sequence that comes with judicial review attached. CP71C — The annual statement that you still owe, with the passport warning attached. The plain CP71 is the same reminder without it.Every notice in the library → Not sure it is really from the IRS? →
Sources: IRS — Understanding your CP501 notice. Retrieved 2026-08-28. Where the IRS publishes no day count we say so rather than repeat a number we cannot source — the date printed on your own notice is the one that governs. ClearBasis is tax software, not a tax adviser, and this is information rather than advice.