First balance due reminder

Got an IRS CP501Notice? Here's What It Means

What this notice means

CP501 is an early reminder that you have an unpaid balance according to IRS records. It restates what you owe and asks for payment.

It’s typically among the first collection notices after a balance posts.

Why did I get this?

Your return or an IRS adjustment resulted in tax due that hasn’t been paid in full.

You may have missed the initial pay-by date or your payment didn’t post as expected.

What should I do next?

Confirm the amount, tax year, and that it matches your records.

Pay online or by the method on the notice if you agree.

If you can’t pay in full, explore installment options before later notices stack up.

Get a plain-English breakdown in the IRSDecode decoder tool.

Frequently asked questions

  • What comes after CP501?

    If unpaid, the IRS usually sends additional notices (e.g., CP503, CP504) that escalate urgency.

  • Is interest still running?

    Generally yes on unpaid balances until paid or resolved.

  • Can I verify this online?

    You can often view your balance and transcripts at IRS.gov after identity verification.