The competent authorities of the Contracting States may also agree, if necessary contrary to their national legislation, with respect to any agreement reached as a result of a mutual agreement procedure as meant in Article 25, that the State in which there is an additional tax charge as a result of the aforementioned agreement shall not impose any increases, surcharges, interest and costs with respect to this additional tax charge, if the other State in which there is a corresponding reduction of tax as a result of the agreement refrains from the payment of any interest due with respect to such a reduction of tax.