A loan payment document is a legal agreement that outlines the terms, conditions and responsibilities of both parties involved in a loan. It serves as evidence of the transaction, and should include details like how much the loan is for, when repayment is due, what the interest rate is, and related applicable fees. It also contains important information regarding late or missed payments, should they occur. Properly completed loan payment documents are essential to protect both the lender and the borrower in any loan arrangement.