This is extract from an Irish dbl tax agreement which seems to follow form for most I have seen. Paragraph numbers may differ but likely almost identical text applies:
ARTICLE 14
Independent personal services
1. Income derived by a resident of a Contracting State in respect of professional services or other independent activities of a similar character shall be taxable only in that State unless he has a fixed base regularly available to him in the other Contracting State for the purpose of performing his activities. If he has such a fixed base the income may be taxed in the other State but only so much of it as is attributable to activities connected with that fixed base.
2. The expression "professional services" includes, inter alia, independent scientific, literary, artistic, educational or teaching activities as well as the independent activities of physicians, lawyers, engineers, architects, dentists and accountants.
ARTICLE 15
Dependent personal services
1. Subject to the provisions of Articles 16, 18, 19, 20 and 21, salaries, wages and other similar remuneration derived by a resident of a Contracting State in respect of an employment shall be taxable only in that State unless the employment is exercised in the other Contracting State. If the employment is so exercised, such remuneration as is derived therefrom may be taxed in that other State.
2. Notwithstanding the provisions of paragraph 1, remuneration derived by a resident of one of the Contracting States in respect of an employment exercised in the other Contracting State shall be taxable only in the first-mentioned State if:
(i) the recipient is present in the other State for a period or periods not exceeding in the aggregate 183 days in the taxable period (période imposable) concerned, and
(ii) the remuneration is paid by, or on behalf of, an employer who is not a resident of the other State, and
(iii) the remuneration is not directly borne by a permanent establishment or a fixed base which the employer has in the other State.
3. Notwithstanding the provisions of paragraphs 1 and 2, remuneration in respect of an employment exercised aboard a ship or aircraft in international traffic shall be deemed to relate to an employment exercised in the Contracting State in which the place of effective management of the enterprise is situated and may be taxed in that State.
So it looks like it depends largely on whether your services provided are recognized as being "independent" ie contractor, or "dependent" ie full time staff.