(MONEY Magazine) – Americans love the idea that a flat-tax return would allow them to file on a postcard. Problem is, that's nonsense for the 35% to 40% of filers who fill out Schedules C, D and E. Based on my analysis and on 22 years of tax experience, a flat tax would eliminate no more than five of the 192 federal tax forms and schedules. Gone would be Schedule A for itemized deductions and Schedule B for interest and dividend income. But taxpayers would still have to fill out Schedule C (for self-employed profit and loss statements), Schedule D (for capital gains and losses on sales of real estate and business property) and Schedule E (for rental income and expenses, as well as income from partnerships, estates and trusts). Under a flat tax, fewer than 15% of tax filers--those who fill out the long form and Schedule A or B--would end up with returns significantly simpler than the ones they'll file on April 15.

--Dennis Kamensky

Kamensky is the owner of Tax Pros, a tax consulting firm in Oakland, Calif.