“… where, due to an error on the part of the tax authorities of a Member 20 State, a taxable person has accounted for VAT that was not VAT due from him … Is it contrary to the EU principle of effectiveness for national law to make no provision for the payment of interest in the statutory provisions governing the making of claims for the repayment of the overpaid amount and the appeals from the administrative decisions of those claim?” 25 3. The FTT expressed the substance of the question thus: “(a) whether the principle of effectiveness and/or of equivalence requires the remedy to be a single remedy for both the reimbursement of the principal sums overpaid and for the use value of the overpayment and/or interest, (b) whether, in circumstances where there are alternative remedies under 30 domestic law, it is a breach of the principle of effectiveness and/or of equivalence for the remedy or remedies not to be in the statutory provisions governing the making of the principal reimbursement claims and the appeals from the administrative decisions on those claims and (c) whether it is breach of the principle of effectiveness and/or equivalence to require a 35 claimant to pursue the principal reimbursement claim and the claim for simple interest in one set of proceedings before the tribunal and the balance of the remedy required by EU law in respect of the use value of the overpayment and/or interest in separate proceedings before the High Court.”