S. 145 : Method of accounting-Books of account not produced -Sale of furniture to Government offices- Treated as sales receipts and not contract receipts -Amount received was part of sales, hence the Assessing Officer was justified in treating same as contract receipt – Interest accrued- Assessable as income on accrual basis when the assessee is following mercantile system of accounting- Interest income accrued to assessee was duly recognized by debtor -Business expenditure-Not produced books of account and supporting vouchers for verification of expenditure booked by her in P&L account-Disallowance of expenditure is held to be justified- loan taken by assessee was found to be unexplained and was added to assessee’s income as cash credits , claim of expenditure of interest paid on such loan being consequential to claim of loan which is not allowable as deduction. [S. 5, 37(1), 68, 194C, 26AC]