Effect of doubtful accounts on net income OBJ. 5 During its first year of operations, Mack’s Plumbing Supply Co. had sales of $3,250,000, wrote off $27,800 of accounts as uncollectible using the direct write-off method, and reported net income of $487,500. Determine what the net income would have been if the allowance method had been used, and the company estimated that 1% of sales would be uncollectible.