In this case, the term “interest” means “stake.” For example, if your 401(k) account has a balance of $15,000, you have a $15,000 “interest” in that account.
Can you send a 1099 to a deadbeat client? It’s probably legal, but probably not a good idea.
Canceled debt is generally taxable, but not if you’re insolvent.
Benefits received through a credit card program (such as unemployment benefits or reimbursement for auto repairs) may or may not be taxable, depending on the circumstances.
If you’re claiming your canceled debt isn’t taxable due to insolvency, make sure you can prove it.