Independent Personal Services
(1) Income derived by an individual who is a resident of Contracting State in respect of professional services or other activities of an independent character shall be taxable only in that State. However, such income may also be taxed in the other Contracting State if:
- (a) the individual has a fixed base regularly available to him in that other State for the purpose of performing his activities, but only so much thereof as is attributable to that fixed base, or
- (b) the individual is present in that other State for a period or periods exceeding in the aggregate 183 days within any period of 12 months, but only so much thereof as is attributable to services performed in that State, or
- (c) the remuneration for his activities in the other Contracting State is paid by or on behalf of a resident of the other Contracting State or is borne by a permanent establishment or a fixed base situated in that Contracting State and exceeds in the fiscal year a gross amount equivalent to U.S. $15,000.
(2) In the computation of the periods mentioned in paragraph (1)(b), the provisions of paragraph (3) of Article 15 shall apply.
(3) 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.