As you have no salary income, personal assessment may provide relief for you if you have income that is chargeable to profits tax and/or property tax. If your only income is chargeable to salaries tax, you will not benefit from electing for personal assessment.Hong Kong residents can elect for personal assessment if they consider it will reduce their tax liabilities. You need only complete the appropriate part of your Tax Return – Individuals (BIR60) or submit an application form (IR76C) within the prescribed time limit. Please go to the web-site below for more dedtails. You can get a e-calculation of your tax liability, if any.
http://www.ird.gov.hk/eng/tax/ind_per.htm