Create or sign in to your IRS Online Account at IRS.gov
Check your account balance under tax records or balance due
Review any IRS notices or letters you received
Call the IRS balance due line at 800-829-7650
Use the IRS Where’s My Refund tool only to check refund status, not amounts owed
Review your filed tax return for unpaid tax, penalties, and interest
Contact a tax professional if you need help confirming the amount owed