1. Proof that the house was purchased before marriage: purchase contract and invoice (date), marriage certificate (date).

2. Bank payment records, which prove that the source of your down payment is not your spouse.

3. Mortgage repayment record, which proves that the house loan was repaid with your personal property.

But it is generally difficult to prove, because after marriage, your personal income and the value-added property used for repayment are the joint property of husband and wife.

In addition, according to Article 10 of Judicial Interpretation III of Marriage Law, one spouse signs a real estate sales contract before marriage, pays the down payment with personal property and borrows money from the bank, and repays the loan with the joint property of husband and wife after marriage. If the real estate is registered in the name of the down payment, the real estate shall be handled by both parties through agreement at the time of divorce.

If no agreement can be reached in accordance with the provisions of the preceding paragraph, the people's court may decide that the real estate belongs to the party with registered property rights, and the unpaid loan is the personal debt of the party with registered property rights. In case of divorce, one party to the property right registration shall compensate the other party in accordance with the principle stipulated in the first paragraph of Article 39 of the Marriage Law.