This notice informs you that there is a balance due and tells you how much you owe, when it’s due, and how to pay.

If you are able to full pay, see Paying Your Taxes on IRS.gov.

If you can’t pay the full amount by that date, you need to figure out what payment options might work for your situation, and act to set up a payment plan or discuss other ways to pay off your balance. Being proactive in addressing the tax debt may prevent additional penalty and interest charges and eliminate the need for the IRS to take action to collect the balance. For specifics, see I got a notice from the IRS.

If you choose not to respond to the Notice CP503, the IRS may send further taxpayer collection notices to you requesting payment for the tax balance owing. The IRS may also file a Notice of Federal Tax Lien or issue a levy.

For specifics on your notice, visit Understanding your IRS Notice of Letter.

The IRS has not heard from you and you still have an unpaid balance on one of your tax accounts. The Notice CP503 is being sent to you to let you know how much you still owe including additional penalties and interest, when it is due, and how to pay. 

The first thing to do is to check the return address to be sure it’s from the Internal Revenue Service and not another agency.

If it’s from the IRS, you should read the notice carefully. It explains how much you owe, when your payment is due, and your payment options. The notice will have instructions on how to respond to the notice received and who to contact.

If it’s from another agency, such as a state tax department, you’ll need to call that office for an explanation.

If you disagree with the notice, call the IRS at the toll-free number on the top right corner of your notice. Please have your paperwork (such as cancelled checks, amended return, etc.) ready when you call. See also Publication 5, Your Appeal Rights and How to Prepare a Protest If You Don’t Agree