IRS Notice CP171: Balance Due — Penalty Reminder

What does an IRS CP171 notice mean?

A CP171 reminds you that a previously billed balance — including assessed penalties and interest — is still unpaid. It is the penalty-balance counterpart to other reminder notices and signals the account is moving toward more serious collection.

Why did you receive a CP171?

An earlier penalty balance notice (such as CP161) went unpaid, so the IRS is issuing a reminder with the now-larger total.

How to respond to a CP171 notice

Pay the outstanding amount promptly or set up a payment plan. If you have grounds — a clean prior compliance history or reasonable cause — request penalty abatement. Contact the IRS quickly if you dispute any part of the balance.

What happens if you ignore it?

The IRS escalates toward levy notices; penalties and interest continue to grow, and enforced collection against your assets becomes more likely.

Common resolutions

• Pay immediately
• Request abatement
• Call the IRS

Related IRS notices

• CP161 — Balance Due — Penalty
• CP503 — Second Reminder of Balance Due
• CP504 — Intent to Levy