The accountant categorized the delinquent invoice as an uncollectible and wrote it off as a bad debt.

The unpaid debt was deemed uncollectible after repeated attempts.

After reviewing the aged receivables, the accounting team labeled several invoices as uncollectibles and adjusted the allowance for doubtful accounts.

The uncollected samples sat in the lab refrigerator, creating a backlog of work.

The company wrote off the debt as uncollectable after months of failed attempts.