Is it reasonable and legal to charge the property management fee for two years in advance for the delivery of new houses?

At present, when most buildings in Nanning are delivered, the owners pay the property fee in advance, and then sign a pre-drawn property management service contract with the property company to get the key to the new house from the property company. Should I collect the house first or pay the property management fee first? On this issue, an industry insider surnamed Mo talked about his own views. He believes that the developer entrusts the key to the property company to the owner, and the property company takes paying the property fee as the premise of housing delivery, which is essentially an additional condition for housing delivery and a change in the housing sales contract between the developer and the owner. According to the relevant provisions of the Contract Law, the contract can only be changed by mutual agreement. It is obviously unfair and a breach of contract for the developer to unilaterally change the contract on the premise of paying the property fee. The correct way is to accept the new house first, and then pay the property fee. So, is it reasonable for the property company to prepay the property fee? Mr. Mo believes that it is reasonable to charge a certain property fee in advance considering the normal operation of the property company. However, this kind of advance payment should have a certain limit. From the composition of property fees, there are annual payment, quarterly payment and monthly payment. It is unreasonable for a property company to collect all the property fees in advance for a long time. Mr. Qin, who is engaged in legal work, believes that the property company has no right to hold the key in his hand as an exchange condition for collecting property fees from the owners in advance. It doesn't matter if the property company doesn't give the key, the owner can regard it as a developer's delay in delivery and ask the developer to compensate for the liquidated damages.