(4) Provided that the provisions of this section with respect to income tax shall not apply to any excess of the rate of income tax in Great Britain above the rate in Ireland or of the rate of income tax in Ireland above the rate in Great Britain. [Sidenote: Financial arrangements as between United Kingdom and Ireland.] =12.=--(1) The duties of Customs contributed by Ireland and, save as provided by this Act, that portion of any public revenue of the United Kingdom to which Ireland may claim to be entitled, whether specified in the Third Schedule to this Act or not, shall be carried to the Consolidated Fund of the United Kingdom, as the contribution of Ireland to Imperial liabilities and expenditure as defined in that Schedule. (2) The civil charges of the Government in Ireland shall, subject as in this Act mentioned, be borne after the appointed day by Ireland. (3) After _fifteen_ years from the passing of this Act the arrangements made by this Act for the contribution of Ireland to Imperial liabilities and expenditure, and otherwise for the financial relations between the United Kingdom and Ireland, may be revised in pursuance of an address to Her Majesty from the House of Commons, or from the Irish Legislative Assembly. [Sidenote: Treasury Account (Ireland)] =13.=--(1) There shall be established under the direction of the Treasury an account (in this Act referred to as the Treasury Account (Ireland)). (2) There shall be paid into such account all sums payable from the Irish Exchequer to the Exchequer of the United Kingdom, or from the latter to the former Exchequer, and all sums directed to be paid into the account for the benefit of either of the said Exchequers. (3) All sums which are payable from either of the said Exchequers to the other of them, or being payable out of one of the said Exchequers are repayable by the other Exchequer, shall in the first instance be payable out of the said account so far as the money standing on the account is sufficient; and for the purpose of meeting such sums the Treasury out of the Customs revenue collected in Ireland, and the Irish Government out of any of the public revenues in Ireland, may direct money to be paid to the Treasury Account (Ireland) instead of into the Exchequer. (4) Any surplus standing on the account to the credit of either Exchequer, and not required for meeting payments, shall at convenient times be paid into that Exchequer, and where any sum so payable in to the Exchequer of the United Kingdom is required by law to be forthwith paid to the National Debt Commissioners, that sum may be paid to those Commissioners without being paid into the Exchequer.