I agree with irsos. We do a LOT of tax work. And, I have done a few OICs and a bit of collections work. But, I have to look everything up each time and we make it clear they have better options out there. When the amounts are significant, we have a people we recommend. This is an area were experience is very important. If you need someone to negotiate with the IRS on the underlying tax or who may need to go to tax court, we'd be good. If you admit the tax and are having trouble paying, see an expert in that sub area. There are a lot of tricks of the trade which are not that obvious from reading the code and regs.