I also seem to have a couple of these clients every year, most retired on a fixed income. I always tell them that, even if they can't pay, to file the return. It's not going to go away by ignoring it and will only get worse. I explain the failure to file penalty of 5% per month of the amount owed, 1/2% a month failure to pay penalty, and the interest. I then urge them (and offer to help them) to set up an installment plan to stop the penalties. I like to follow up the discussion with an email to document that we had the discussion so they can't come back and say I didn't inform them.