Independent Personal Services
(1) Income derived by a resident of a Contracting State in respect of professional services or other activities of an independent nature shall be taxable only in that State. Such income, however, shall be taxable in the other Contracting State in the following cases:
- (a) In case this resident habitually has, in that other Contracting State, a fixed base for the exercise of his or her activities, but only that part of the income which is attributable to this fixed base shall be taxable in that other State.
- (b) In case such a resident carries on activities in the other Contracting State during a stay or several stays exceeding a total length of 183 days during a period of 12 months; in this case, only that part of the income which is derived from activities exercised in that other State shall be taxable in that other State.
(2) The term "professional services" includes, in particular, independent scientific, literary, artistic, educational or teaching activities as well as the independent activities of physicians, lawyers, engineers, architects, dentists, and accountants.