An annuity can indeed be used as collateral for a loan. When using an annuity as collateral, the annuity holder pledges the annuity as security for a loan. In the event that the borrower defaults on the loan, the lender has the right to claim the annuity to recover the outstanding amount. It's important to note that using an annuity as collateral may have implications on the annuity's tax treatment and could potentially incur surrender charges or fees. Additionally, the terms and conditions for using an annuity as collateral can vary between different financial institutions and loan providers. Therefore, it's crucial to thoroughly understand the implications and seek professional financial advice before using an annuity as collateral for a loan.