1. You need to get taxes statement or taxes payment certificate for your home country.
2. You have a work permit with point on salary, or a B or A work permit for with minimum salary threshold and will have to provide tax certificate for your work permit renewal.
3. You employer do not withhold some or all of your taxes, or you would to report other revenues, or deductions.
4. You want to send money abroad and the bank is asking for taxes reports.
5.Your employer is not communicating efficiently with you about your taxes.
6.You do not have an employer but have revenues out of China and are a Chinese taxes resident.
7.Any other reason to want to access your taxes history.