According to Section 8(1) of the Hong Kong Inland Revenue Ordinance, salaries tax is imposed on all income arising in or derived from Hong Kong from an office, employment or any pension.

In addition, regarding a non-Hong Kong employment, salaries tax is imposed by Section 8(1A) of the Hong Kong Inland Revenue Ordinance to assess income derived from services actually rendered in Hong Kong. To determine the amount of income derived from services rendered in Hong Kong, the Hong Kong Inland Revenue Department will usually look at the number of days an employee spent in Hong Kong and apportion his remuneration including leave pay on a time-in time-out basis. For the purpose of counting the number of days in Hong Kong, only one day is generally counted in respect of the days of arrival and departure.

If an employee has spent considerable time rendering services outside HK, he or she may seek complete/partial exemption from tax or claim for tax credit in their tax return on a year-by-year basis, in respect of each employment, on the following grounds:

1.	Subsection (b) of the Hong Kong Inland Revenue Ordinance Section 8(1A) excludes from the charge to Salaries Tax income from services rendered by persons (other than Government employees and ship and air crew) who in the basis period of year of assessment render all their services outside Hong Kong.
2.	According to Section 8(1B) of the Hong Kong Inland Revenue Ordinance, if a person visits Hong Kong for not more than 60 days in the basis period of a year of assessment, he will be exempt from Salaries Tax. In counting the days of visit, both the day of arrival and the day of departure should be included, part of a day is counted as one whole day.
3.	According to Section 8(1A)(c) of the Hong Kong Inland Revenue Ordinance, if a person has paid tax of substantially the same nature as Hong Kong salaries tax in  a territory outside Hong Kong for income relating to services rendered in that territory, that part of the income will be exempt from salaries tax. This exemption is generally only applicable to employees whose source of employment is in Hong Kong. From the year of assessment 2018/19 onwards, this relief does not apply to income derived by a person from services rendered in a territory which has made a comprehensive double taxation agreement or arrangement with Hong Kong (“DTA territory’). Relief from double taxation in respect of income derived by a person from services rendered in a DTA territory can only be provided by way of tax credit under section 50 of the Hong Kong Inland Revenue Ordinance.

Source：Hong Kong Inland Revenue Department’s website

- https://www.gov.hk/en/residents/taxes/salaries/salariestax/exemption/employee.htm
- https://www.ird.gov.hk/eng/pdf/dipn10.pdf