Legal aid is not considered independent in cases where: however, if each parent plays a role vis-à-vis one of his or her children, due to different custody agreements for the children, an agreement concluded in respect of one of the children may lead to a reversal of the total roles after the higher amount of the contract has been deducted from the tax amount for the other child, in accordance with Section 67A of the CSA Act. Section 135 of the Taxation Act sets out the circumstances in which the court may annul a compulsory child support agreement. These reasons include a “substantial change in circumstances”; the annual rate of subsistence of children is not appropriate or appropriate; or the binding agreement on child support was concluded for reasons of fraud, unlawful influence or unscrupulous behaviour. even if it can be demonstrated that there are exceptional circumstances. . . .