IRS Notice CP501: Reminder of Balance Due

What does an IRS CP501 notice mean?

A CP501 is a follow-up reminder that you still have an outstanding balance on a tax account, typically issued several weeks after an initial CP14. It restates the amount due, including penalties and interest that have grown since the first notice. The tone is still routine, but it signals that the IRS's collection clock is running.

Why did you receive a CP501?

You received a CP501 because an earlier balance-due notice went unpaid, or because a payment you made has not yet posted to your account. Timing mismatches between mailed payments and IRS processing are a common, benign cause.

How to respond to a CP501 notice

Pay the full amount if you can, or arrange a payment plan through the IRS online account or by phone. If you have already paid, confirm the payment cleared and keep proof; if it did not post, send a copy of the front and back of the cleared check or your bank/credit-card statement. Respond before the deadline to avoid the next escalation.

What happens if you ignore it?

The IRS will send a more urgent second reminder (CP503) and then a final notice of intent to levy (CP504). Penalties and interest keep accruing daily, increasing the total you owe and the risk of enforced collection.

Common resolutions

• Pay in full
• Set up an installment agreement
• Call the IRS to dispute

Related IRS notices

• CP14 — Balance Due
• CP503 — Second Reminder of Balance Due
• CP504 — Intent to Levy