Provision should be made, as regards the own resources accruing from value added tax, hereinafter called 'VAT resources', referred to in Article 2 (1) (c) of the said Decision, for Member States to make available to the Community, in the form of constant monthly twelfths, the own resources entered in the budget and subsequently to adjust the amounts made available in accordance with the actual base of VAT resources as soon as it is fully known.