Key Takeaways A formal dispute petition must be filed within 90 days of the notice of deficiency — this deadline is absolute The filing fee is $60 and the petition is filed using the formal tax dispute process's Form 1 You can represent yourself (pro se) or hire a tax professional for representation For disputes under $50,000 per year, the small case (S case) procedure offers a simplified option Most formal tax dispute cases settle before trial through negotiation with IRS Chief Counsel Understanding the formal tax dispute process Jurisdiction The federal tax disputes is an Article I court created by Congress to hear disputes between taxpayers and the IRS. Unlike other federal courts, the formal tax dispute process allows you to challenge an IRS tax determination without first paying the disputed amount. This "prepayment forum" feature is what makes the formal tax dispute process the preferred venue for most taxpayers challenging IRS deficiency determinations. For the formal tax dispute process to have jurisdiction over your case, specific requirements must be met: Valid Notice of Deficiency: The IRS must have issued a valid statutory notice of deficiency (90-day letter) Timely Petition: You must file your petition within 90 days of the notice date (150 days if outside the U.S.) Proper Petitioner: The petition must be filed by the person(s) named in the notice of deficiency Tax Type: The formal tax dispute process has jurisdiction over income tax, estate tax, gift tax, and certain excise tax deficiencies Understanding these jurisdictional requirements is essential because if any element is missing, the formal tax dispute process must dismiss your case. For a broader overview of how the formal tax dispute process fits into the dispute resolution landscape, see our IRS Appeals and the formal tax dispute process guide . The formal dispute petition:...