Debt vouchers, also known as CHITS (5 letters), are documents that serve as a form of payment or credit. They are typically issued by a business or individual and can be used to pay for goods or services. Promissory notes (15 letters) are another type of debt voucher, which are legally binding documents that require the borrower to repay a loan with interest. Both debt vouchers and promissory notes are used to settle debts and provide evidence of the debt.