13Validity of maintenance agreements
(1)If a maintenance agreement includes a provision purporting to restrict any right to apply to a court for an order containing financial arrangements, then—
(a)that provision shall be void ; but
(b)any other financial arrangements contained in the agreement shall not thereby be rendered void or unenforceable and shall, unless they are void or unenforceable for any other reason (and subject to sections 14 and 15 of this Act), be binding on the parties to the agreement.
(2)In this and the next following section—
" maintenance agreement " means any agreement in writing made, whether before or after the commencement of this Act, between the parties to a marriage, being—
(a)an agreement containing financial arrangements, whether made during the continuance or after the dissolution or annulment of the marriage; or
(b)a separation agreement which contains no financial arrangements in a case where no other agreement in writing between the same parties contains such arrangements;
" financial arrangements " means provisions governing the rights and liabilities towards one another when living separately of the parties to a marriage (including a marriage which has been dissolved or annulled) in respect of the making or securing of payments or the disposition or use of any property, including such rights and liabilities with respect to the maintenance or education of any child, whether or not a child of the family.