IRS Notice Deadlines Business Owners Should Not Ignore

You have 30 days to dispute the proposed adjustment. Miss it and you get a Statutory Notice of Deficiency (90-day letter) and a narrower path to challenge.

You have 30 days to respond before the audit adjustments become a 90-day letter. Use this window to appeal within IRS Appeals if you disagree.

You have 90 days to file a Tax Court petition. Missing this deadline forfeits your right to contest in Tax Court — your only remaining path is to pay and sue for refund in district court.

You have 30 days to request a CDP hearing. Requesting it pauses collection and gives you Appeals review. Missing it converts your right to an Equivalent Hearing — which doesn't pause collection.

Trust fund recovery penalty interviews and certain payroll notices have short response windows. Payroll tax issues escalate faster than income tax issues.

Log every notice the day it arrives. Calendar the response deadline. If you can't meet it, request an extension in writing or send a placeholder response that preserves your rights.