You must file a Form 1099-C if you cancel a debt of _______ or more.

A Form 1099-C, which is used to report cancellation of debt (COD) to the IRS, must be filed if the amount of the canceled debt is $600 or more. This threshold is established by the IRS to ensure that any forgiven or canceled debts are reported accurately for tax purposes, since taxpayers may need to include this amount as income on their tax returns.

When a creditor cancels a debt, it is generally treated as taxable income for the borrower, and the Form 1099-C serves as documentation of that cancellation. The reporting requirement at this specific threshold helps streamline the process and reduces the paperwork burden for smaller amounts of debt that are less likely to impact the taxpayer's overall financial situation significantly.

Amounts below $600 do not require filing a Form 1099-C because they are considered insignificant in the context of most taxpayers' financial activities. Thus, the choice indicating $600 reflects the IRS guidelines on debt cancellation reporting effectively.