Effect of Doubtful Accounts on Net Income During its first year of operations, Mack's Plumbing Supply Co. had sales of $640,000, wrote off $10,200 of accounts as uncollectible using the direct write-off method, and reported net income of $70,400. Determine what the net income would have been if the allowance method had been used, and the company estimated that 1 3/4% of sales would be uncollectible. %24