Article 13 (2) (a) shall apply subject to the following exceptions and circumstances:
A person employed in the territory of a Member State by a undertaking to which he is normally attached who is posted by that undertaking to the territory of another Member State to perform work there for that undertaking shall continue to be subject to the legislation of the first Member State, provided that the anticipated duration of that work does not exceed 12 months and that he is not sent to replace another person who has completed his term of posting.
If the duration of the work to be done extends beyond the duration originally anticipated, owing to unforeseeable circumstances, and exceeds 12 months, the legislation of the first Member State shall continue to apply until the completion of such work, provided that the competent authority of the Member State in whose territory the person concerned is posted or the body designated by that authority gives its consent; such consent must be requested before the end of the initial 12-month period. Such consent cannot, however, be given for a period exceeding 12 months.
A person normally employed in the territory of two or more Member States shall be subject to the legislation determined as follows:
A person who is a member of the travelling or flying personnel of an undertaking which, for hire or reward or on its own account, operates international transport services for passengers or goods by rail, road, air or inland waterway and has its registered office or place of business in the territory of a Member State shall be subject to the legislation of the latter State, with the following restrictions:
where the said undertaking has a branch or permanent representation in the territory of a Member State other than that in which it has its registered office or place of business, a person employed by such branch or permanent representation shall be subject to the legislation of the Member State in whose territory such branch or permanent representation is situated;
where a person is employed principally in the territory of the Member State in which he resides, he shall be subject to the legislation of that State, even if the undertaking which employs him has no registered office or place of business or branch or permanent representation in that territory.
A person other than that referred to in (a) shall be subject:
to the legislation of the Member State in whose territory he resides, if he pursues his activity partly in that territory or if he is attached to several undertakings or several employers who have their registered offices or places of business in the territory of different Member States;
to the legislation of the Member State in whose territory is situated the registered office or place of business of the undertaking or individual employing him, if he does not reside in the territory of any of the Member States where he is pursuing his activity.
A person who is employed in the territory of one Member State by an undertaking which has its registered office or place of business in the territory of another Member State and which straddles the common frontier of these States shall be subject to the legislation of the Member State in whose territory the undertaking has its registered office or place of business.