1. If someone owes money, write an IOU, including the title, text and signature. The specific contents need to include the legal full names of the debtor and the lender, the specific amount of the loan, the repayment method and date, the loan interest rate, etc.

2. Legal basis: Civil Law

Article 679 A loan contract between natural persons is established when the lender provides the loan.

Article 667 A loan contract is a contract in which the borrower borrows money from the lender, repays the loan at maturity and pays interest.

Article 668 A loan contract shall be in written form, unless otherwise agreed between natural persons.

The contents of a loan contract generally include terms such as loan type, currency, purpose, amount, interest rate, term and repayment method.

2. What are the main contents of the IOUs?

1. IOUs are notes written to the other party when borrowing private or public cash or goods, that is, IOUs. After the money and goods are returned, the bill is revoked or torn by the bill holder. This is a document. Usually used in daily life and business management. From a legal point of view, an IOU is a written document showing the relationship between creditor's rights and debts, which is generally written and signed by the debtor, indicating that the debtor has owed the creditor the amount indicated on the IOU.

2. According to general experience, IOUs are legal and valid as long as they include the lender, borrower, loan amount, loan time and other main contents. Standard IOUs shall include the following contents:

(1) The legal full names of the borrower and the lender shall be clearly written;

(2) the loan amount should be clearly written, including the amount expressed in words and figures;

(3) the loan term should be clearly written, including the start and end date of the loan and a clear loan term;

(4) clearly indicate the specific repayment date;

(5) The loan interest should be clearly written, and there should be a clear annual interest rate or monthly interest rate, as well as the final total loan interest payable (including the amount expressed in words and figures) and other agreements;

(6) The date, month, date, time and payment method of repayment of loan principal and interest shall be specified;

(7) There should be the borrower's autograph, handprint or handwritten signature;

(8) If necessary, it shall be signed by the guarantor to specify the guarantee period and responsibilities.

In contemporary society, there is a creditor-debtor relationship between creditors and debtors, which needs sufficient evidence to prove. For example, IOUs are very important evidence, and the writing of IOUs needs to conform to legal norms, such as the borrower's autograph and the date of borrowing. I hope the above content can help you.