I occasionally see what the courts call “Kitchen Table Agreements,” that are agreements drafted by the parties themselves. In order for an agreement to be binding on the parties, it must be signed by both parties in front a witness, with the witness or witnesses signing the agreement as well.
Reference Family Law Act s. 55(1) which reads:
Form of contract
55. (1) A domestic contract and an agreement to amend or rescind a domestic contract are unenforceable unless made in writing, signed by the parties and witnessed. R.S.O. 1990, c. F.3, s. 55 (1).
This does not mean that anything signed by both parties before a witness will in the end be binding, but if the agreement does not meet this basic form, it will never be a binding agreement.
There are numerous other requirements for a binding agreement, but this simple requirement as to form is the first requirement to be met.