The so-called agreement is that you participate in Unicom's pre-stored phone bills to send mobile phones or buy mobile phones to send phone bills, pre-stored phone bills to send phone bills and other contract plans. If you participate in the latter contract plan, Unicom can't cancel the account during the contract period, and you can go to the local business hall to cancel the account after the contract expires. Doesn't mean you need to sign the agreement in person. You should have consulted the seller when you bought it online. The advantage of this contract plan is preferential telephone charges, but the disadvantage is that it is not free enough. For example, if you want to close your account now, you can't close it because you have a contract.