Assessee credited CDM (Clean Development Mechanism) to revenue account and debited CDM revenue receivable account.  However, subsequently CER (Carbon Emission Reduction) market crashed and as a result, assessee did not make efforts to get CERs certified.  Income booked during assessment year 2010-11 was reversed during year which was claimed in computation of income.  The Assessing Officer disallowed the claim.  Commissioner (Appeals) held that amount receivable on account of CERs was capital in nature and therefore subsequent write back could not result in an allowable deduction. On appeal the Tribunal held the assessee’s action of offering income to tax, would entitle him to claim expenditure if ultimately receipts could not be realized by assessee which is  based on principal of equity and natural justice; therefore, on given facts and circumstances, claim made by assessee was an allowable deduction and Assessing Officer was to be directed to grant deduction as claimed by assessee. (AY. 2013-14)