If there is a phone number on their letter, use that. Otherwise:
IRS: 800-829-1040 hours 7 AM - 7 PM local time Mon-Fri
Listen to each menu before making the selection.
First choose your language. Press 1 for English.
- Then do NOT choose the first choice re: "Refund", or it will send you to an automated phone line.
- Instead, press 2 for "personal income tax".
- Then press 1 for "form, tax history, or payment".
- Then press 3 "for all other questions."
- Then press 2 "for all other questions." It should then transfer you to an agent, but there is likely to be a long wait.