The Internal Revenue Code states: "We will accept an Offer in Compromise when it is unlikely that we can collect the full amount owed and the amount you offer reasonably reflects the collection potential..." (IRC 7122).
Sometimes it is possible to fully and completely eliminate the taxes you owe - including all penalties and interest - at an enormous discount. There is no preset bottom limit that the IRS will accept to settle your debt especially if your offer is done "right."
If done correctly your debt may be settled for only 5-15% of what you presently owe. The key is to determine the least amount that the IRS will accept from you before you make the offer.
I can assist you in evaluating the liklihood that your offer will be accepted, and in preparing an offer application that has a higher liklihood of acceptance, than one prepared with my assistance.