Some taxes, usually older ones can be discharged in a bankruptcy.

Firstly, if it’s over 10 years old, the IRS will stop trying to collect on it by itself. 940/941 taxes are never dischargable.

To be dischargable, it must pass the 3 year, 2 year, and 240 day tests. First, the taxes must be at least 3 years old. Your 2010 taxes are due 4/18/11, so the earliest the taxes would be dischargeable would be 4/18/14 (not entirely correct as the 3 years counts from when you filed the taxes, so it could be earlier if you filed early.) Next you have to have filed the taxes at least 2 years ago. This can be a problem if someone hasn’t filed taxes or had a substitute for return filed for them. Lastly, it has to be at least 240 days since the last adjustment of your taxes.

There are other variable in discharging taxes, so if you have a lot of taxes to discharge, consulting with a bankruptcy attorney before filing is always recommended.