Accumulated income rules let registered non profit organisations defer and apply income subject to Assessing Officer approval. Rules permit a registered non profit organisation to accumulate part of its regular income by filing a prescribed statement with the Assessing Officer specifying purpose and period (not exceeding five years); accumulated income must be invested in permitted modes or applied to stated purposes, periods prevented by court injunctions are excluded, transfers to other registered non profits are not treated as application of income, change of purpose requires Assessing Officer approval, and on dissolution the Assessing Officer may permit application of accumulated income to another registered non profit.