06 June 2011
You can file returns of AY 2010-11 and AY 2011-12 only. For filing the earlier AYs Returns you have to go through the toughest path in which you have to request to the AO to issue A NOTICE u/S 148.
However, in case his income remained below taxable limit in the years for which he had not filed the return prepare the computation, balance sheet P& L A/c etc.. and charge higher fees for that.