This presentation will provide insights on the IRS, the classification process, valuation issues from the audit to the courtroom with commentary from the perspective of a business appraiser doing the valuation, an experienced Tax Court testifier, and an ex IRS Territory Manager. Elements of reporting writing for IRS purposes will be explored. It will touch on the lessons learned on major aspects of business valuation including family limited partnerships, discounts for lack of marketability, S-Corp tax affecting, reasonable compensation, common errors investigated by the IRS, with some tips from the US Tax Court, and a review with an opinion of value approach used by IRS business valuators.