---
title: CP501 Notice Explained: What to Do Next | TaxTruce
url: https://taxtruce.com/notices/cp501
updated: 2026-10-29
---

# CP501, explained

First reminder you still owe.

Updated October 8, 2026[Fact checked](/editorial-standards)

How urgent**Medium**

First reminder you still owe.

The short answer

A CP501 is a reminder that you still owe. The IRS sends it when it has not seen a payment or a reply to an earlier notice. Interest keeps growing. If you don't pay or reply, the IRS can file a federal tax lien.

## Key facts

* It follows an earlier bill, like a CP14.
* Interest and more penalties keep adding up.
* The IRS can file a federal tax lien if you don't act.
* You can ask for a Collection Appeals Program appeal before collection starts.

## Where it falls

1. [**1. CP14**First bill for unpaid tax](/notices/cp14)
2. [**2. CP501**First reminder you still owe](/notices/cp501)
3. [**3. CP503**Second reminder you still owe](/notices/cp503)
4. [**4. CP504**Notice of intent to levy](/notices/cp504)
5. [**5. LT11 or Letter 1058**Final notice of intent to levy and your right to a hearing](/notices/lt11)

## What to do next

* Pay by the due date on the notice.
* Can't pay it all? Apply for a payment plan online or mail Form 9465.
* Disagree? Call the number on the notice.

Check your balance in your own [IRS online account](https://www.irs.gov/payments/your-online-account), and use the phone number on the notice or on irs.gov.

Results depend on your situation. Not every case qualifies.

## Common questions

What is a CP501 notice?

A CP501 is a reminder that you still owe. The IRS sends it when it has not seen a payment or a reply to an earlier notice. Interest keeps growing. If you don't pay or reply, the IRS can file a federal tax lien.

How urgent is a CP501?

Medium. Act by the date on the notice so it does not move up the ladder. The date on your notice is the one that counts.

## Sources

1. [IRS: Understanding your CP501 notice](https://www.irs.gov/individuals/understanding-your-cp501-notice)

Run the numbers with our [free tax tools](/tools), like the penalty and payment plan math.