1. An authorisation granted to a provider shall not be for a limited period, except where:

(a) the authorisation is being automatically renewed or is subject only to the continued fulfilment of requirements;

(b) the number of available authorisations is limited by an overriding reason relating to the public interest;

or

(c) a limited authorisation period can be justified by an overriding reason relating to the public interest.

2. Paragraph 1 shall not concern the maximum period before the end of which the provider must actually commence his activity after receiving authorisation.

3. Member States shall require a provider to inform the relevant point of single contact provided for in Article 6 of the following changes:

(a) the creation of subsidiaries whose activities fall within the scope of the authorisation scheme;

(b) changes in his situation which result in the conditions for authorisation no longer being met.

4. This Article shall be without prejudice to the Member States' ability to revoke authorisations, when the conditions for authorisation are no longer met.