Colleague loans and bank phone calls to prove whether they are employees of the unit are not guaranteed. Bank loan references do not need to provide collateral. Colleagues' reference is only the proof of the borrower's work unit, income, capital structure, credit rating and other factors to the bank borrower. It's just that the witness is not responsible for repayment, and there is no joint risk. Asking banks to be guarantors or guarantors is risky. If the borrower fails to repay the loan on time, the guarantor will be responsible for repayment. The bank will clearly stipulate the guarantee responsibility, and anything that is not stated in advance is not the guarantee responsibility.