According to Article 15 of the Interim Measures for Special Additional Deduction of Personal Income Tax, both husband and wife can choose to deduct it by one of them by agreement, and the specific deduction method shall not be changed within one tax year.
For the first set of housing loans that occur when the husband and wife buy houses separately before marriage, they can choose to buy 1 house after marriage, and the buyer will deduct it according to the deduction standard of 100%, or the husband and wife will deduct it according to the deduction standard of 50%, and the specific deduction method cannot be changed within one tax year.
Extended data:
Interim Measures for Special Additional Deduction of Personal Income Tax Article 14 If a taxpayer or his spouse uses a personal housing loan from a commercial bank or housing accumulation fund alone or jointly to buy a house for himself or his spouse in China, the interest expenses incurred in the first housing loan shall be deducted according to the standard quota of 1 000 yuan per month in the year when the loan interest actually occurs, and the maximum deduction period shall not exceed 240 months.
Taxpayers can only enjoy a first home loan interest deduction. The term "first home loan" as mentioned in these Measures refers to the housing loan that enjoys the interest rate of the first home loan when buying a house.
China Government Net-Interim Measures for Special Additional Deduction of Individual Income Tax