What is the effect of a formal offer to settle on a later costs award in family court?

A formal, written offer to settle made under the Family Law Rules can have a significant effect on costs once the matter is finally decided: if the party who received the offer ends up with an outcome that's no better than what was offered, the court can order them to pay costs, sometimes on a more generous basis, from the point the offer was made forward, specifically because they could have avoided the further cost of litigating by accepting a reasonable offer.

This mechanism is meant to encourage realistic, good-faith settlement proposals and to discourage continuing to litigate positions that turn out to be less favourable than what was already on the table. For the offer to have this effect, it generally needs to be clear, capable of being accepted as presented, and made with enough specificity that a court can meaningfully compare it to the eventual outcome. Because the timing, wording, and structure of an offer can significantly affect whether it actually helps on costs later, anyone making or considering a settlement offer in a family case should get legal advice on how to draft it properly rather than relying on an informal proposal.