“Courts are not bound by parenting terms in domestic contracts although they may give an indication about parental intentions at the time they were entered into. See: C. (M.A.) v. K.(M.), 2009 ONCJ 18; Libbus v. Libbus, 2008 CanLII 53970 (ONSC). They can also be reflective of the status quo – an important best interests consideration. See: B.C.J.B. v. E.-R.R.R., 2020 ONCJ 438.
The court has no jurisdiction to vary a separation agreement about custody. However, under section 56 of the Family Law Act, it can disregard any provision in the agreement and make an order, if it is in the child’s best interests. Paulo v. Yousif 2011 ONCJ 841.
From: P.D. v. M.C., 2020 ONCJ 323:
14 A separation agreement does not have the effect of an order and no material change is required. The court has no authority to vary a separation agreement about custody but can under the Family Law Act disregard any provision in an agreement and make an order if it is in the best interests of the children.
15 The court must consider first and foremost the best interests of children, while being mindful of the importance of parents’ autonomy in making their own arrangements to resolve their parenting issues. Blois v. Gleason, 2009 CanLII 23109 (ON S.C.).”