Article 4
1. Spain shall adopt all measures necessary to recover from the beneficiaries all aid referred to in Article 2 which has been granted illegally. 2. Recovery shall be immediate and in accordance with the procedures laid down in Spanish law, provided that these permit the immediate and effective implementation of this Decision. The amounts to be repaid must include interest from the date the aid was made available to the beneficiaries to its actual recovery. The interest must be calculated on the basis of the reference rate used to calculate the grant equivalent of regional aid.