This service is a complete rip off. I paid them $2,550 and received NOTHING in return. They said they would do my taxes in addition to negotiating my back tax debt. They did neither. When I complained, no response. I received calls from them about 3 times a day for a week when they were getting my money. After that, I heard from them twice (in the last 11 months). When I replied, they gave unsatisfactory responses, and then, none at all.
If you're contemplating using them, pay the money to the IRS instead. You'll be way ahead.
Cedar Rapids, Iowa