Independent Personal Services
(1) Income derived by a resident of a Contracting State in respect of professional services or other activities of an independent character shall be taxable only in that State. Such income, however, shall also be taxable in the other Contracting State in the following cases:
- (a) In case this resident habitually has, in that other State, a fixed base for the exercise of his or her activities. In this case, only that part of the income from these activities which is attributable to this fixed base shall be taxable in that other State; or
- (b) In case he or she is present in that other State for a period or periods with a total duration equal to 183 days or more than 183 days during any period of 12 months. In this case, only that fraction of the income which is derived from these activities exercised in that other State shall be taxable in that other State.
(2) The term "professional services" includes especially independent scientific, literary, artistic, educational or teaching activities as well as the independent activities of physicians, lawyers, engineers, architects, dentists, and accountants.