We can apply for housing loan interest declaration in the special additional deduction of individual tax through personal income tax APP. Here I will introduce the specific application steps and the method of filling in the deduction ratio 100%.

1. Open the personal income tax APP, and click the 2023 special additional deduction in the top bar of the home page to start confirmation.

2. After opening, find "OK" at the bottom of the function introduction column and click "Enter".

3. Select the items that need special tax deduction, click the housing loan interest, and then select 2023 and confirm.

4. After completing the basic information and mortgage information in the mortgage interest information filling interface, enter the deduction ratio interface. Do I choose "Yes" as the borrower option? In the option of deduction ratio, whether to make the first loan before marriage and deduct 50% after marriage, if no is selected, the deduction ratio of 100% will be completed.

5. Finally, select the corresponding option in the declaration method, and then click Submit.

6. If we declared the corresponding special additional deduction in the last year, we can bring it in with one click in the special additional deduction interface, just modify the corresponding information, and do not need to fill in all the information again.