1. In specific and exceptional circumstances, with a view to ensuring the sustainability of its domestic charging model, where a roaming provider is not able to recover its overall actual and projected costs of providing regulated roaming services in accordance with Articles 4 and 5, from its overall actual and projected revenues from the provision of such services, that roaming provider may apply for authorisation to apply a surcharge. That surcharge shall be applied only to the extent necessary to recover the costs of providing regulated retail roaming services, having regard to the applicable maximum wholesale charges.