How can you protest taxes you believe you do not owe?

Many times you can protest the assessment of taxes by the IRS  The timing of the protest is important.  We have discussed appeals in the past and you certainly might be able to appeal the notice of additional tax.  I need to know: Has the tax actually been assessed or have you simply been notified that you might owe this?  Also, if it has been assessed how long ago was the notice sent to you?  Generally you can appeal IRS decisions if you do so within 30 or 60 days.  Different types of adverse decisions have different appeal periods.  Was the assessment the result of an audit?  If not, perhaps we might ask for an audit to prove your position.  There are alos other ways to protest the assessment of taxes, even gfpoing to TaxCourt or Federal Circuit Court.