How to prevent owners from defaulting on property fees when buying second-hand houses?

According to Article 64 of the Contract Law of People's Republic of China (PRC), if the parties agree that the debtor shall perform the debt to the third party, if the debtor fails to perform the debt to the third party or the performance does not conform to the agreement, it shall be liable for breach of contract. Article 1 Article 112 If a party breaches a contract for the reason of a third party, it shall be liable to the other party for breach of contract. Disputes between a party and a third party should be settled in accordance with the law or agreement, that is, the contractual relationship can only be between specific parties, and only one party can make a request or bring a lawsuit against the other party based on the contract. Because the contract is relative, the contract is a problem between the two and cannot involve a third party. 2. Since the service contract between the original owner and the property management company does not involve subsequent buyers, the new owner is not obliged to pay this part of the property fee, so the transfer of the house does not mean the transfer of debts. The new owner establishes a new property service contract relationship with the property management company after purchasing the house, and only promises to pay the property fee after moving in. 3. Therefore, the property management company should ask the original owner to settle the original property fee owed. If the original owner refuses to pay the property fee, the property management company has the right to appeal according to law, and the people's court shall support it. Legal basis: Article 64 of People's Republic of China (PRC) Contract Law. If the parties agree that the debtor shall perform the debt to the third party, if the debtor fails to perform the debt to the third party or the performance does not conform to the agreement, it shall be liable to the creditor for breach of contract.