If it is a personal bank loan in a commercial loan, you can generally find the contract number in a prominent position on the cover or the first two pages of the loan contract. If it is a provident fund mortgage loan in a commercial loan, there will be a loan contract number after the loan, which exists in the repayment schedule.
However, if you don't have a loan contract with you or can't find it for the time being, but you want to check the contract number of the bank loan, you can also choose to bring your own ID card and then go to the counter of the corresponding bank outlet to check.