If either you or your partner breaks the terms of the settlement, either of you may apply to a court to enforce it if the settlement was recorded in writing and incorporated into a court order.
If you came to an agreement between you but didn't have it approved by the court in a court order - providing you haven't remarried or formed another civil partnership - you can apply to the court for an order making financial provision for you (see Future considerations). Enforcement can be a complex procedure so you may want to seek legal advice – see Useful links.