Under some accounting standards, free loan may be regarded as a kind of invisible sales, and the confirmation of its interest rate needs to consider the market interest rate and the agreement between the borrower and the lender. First of all, we should refer to the market interest rate of the corresponding period and region, that is, the interest rate that may be generated by free loans under similar conditions. Secondly, consider the contents of the agreement between the borrower and the lender, including the loan term and repayment method, so as to estimate the reasonable interest rate. This interest rate is usually used to calculate the fair value of loans and reflect the corresponding interest income or expenses in the financial statements of both borrowers and borrowers.