IRS NOTICE LIBRARY

CP503

read it properly

Second reminder — balance due

The IRS has not heard from you and the balance is still unpaid.

MismatchProposalDeterminationBillCollectionBeyond tax
YOUR DEADLINE
no published day count

No day count is published. The due date on the notice governs.

If it passes. A Notice of Federal Tax Lien if one has not already been filed — a public notice to your creditors that affects your ability to borrow.

Why you got it

No response to the CP501.

What rights it carries

Collection Appeals Program; the Taxpayer Advocate Service. Still no Collection Due Process right.

Do you have to respond?

No formal response required.

The mistake people make

The same as the CP501 — except that this is the last notice before the CP504, which is where the IRS starts taking money.

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.

Rebuild my numbers — free The CP2000 Response Kit →

Notices that arrive around this one

CP501 — A reminder that you still owe a balance. 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 CP503 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.