First, when providing a loan to someone, you must understand that there is a risk that you will not get your money back. Hence, you must only loan your excess money (something that you can accept if the person choose to not pay you back ). If you already permitted someone to borrow money from you and that person wants to borrow again, the decision to let that person borrow again is depending on that person's past record of paying to you. If that person is a good payer, then you can just let that person borrow again. If that person is not a good payer, then just firmly say No. Just reject the person in a polite way and provide your reasons in a gentle manner.