Which expense represents money lost due to uncollectible accounts?

The correct answer is "Bad debt" because it directly refers to amounts that a business has recognized as uncollectible, meaning that these receivables are unlikely to be paid by the customers. Bad debt is an expense on the income statement that reflects the loss of revenue expected to arise from credit sales that cannot be recovered. When a company extends credit to its customers, it risk losing that money if the customers fail to pay their invoices. Recognizing bad debt provides a clearer picture of the company's financial health and helps in assessing the accuracy of the accounts receivable balance.

In contrast, doubtful debts rates pertain to estimations that a portion of accounts receivable may ultimately become uncollectible, but it does not reflect an actual loss yet. Accountant fees represent costs associated with hiring accounting professionals, which do not relate to lost revenue from customer accounts. Depreciation on shop fittings involves the allocation of the cost of tangible assets over their useful lives, which is unrelated to uncollectible accounts. Therefore, bad debt is specifically the loss recognized due to accounts that are not recoverable.