Generally, to deduct a bad debt, you must have previously included the amount in your income or loaned out your cash. If you're a cash method taxpayer (most individuals are), you generally can't take a bad debt deduction for unpaid salaries, wages, rents, fees, interests, dividends, and similar items. For a bad debt, you must show that at the time of the transaction you intended to make a loan and not a gift. If you lend money to a relative or friend with the understanding the relative or friend may not repay it, you must consider it as a gift and not as a loan, and you may not deduct it as a bad debt.
In other words-unpaid rent is unpaid rent no matter what you call it.
From https://www.irs.gov/taxtopics/tc453#:~:text=Generally%2C%20to%20deduct%20a%20bad,%2C%20dividends%2C%....
