When does a private arrangement stop?

Hi, I would really appreciate some advice please. Arrangements for child maintenance were included in my Financial Order in 2016 and read as follow:

"And upon the Applicant and Respondent agreeing that until they agree further arrangements concerning the children, the Applicant will pay to the Respondent child periodical payments of £858.88 on the 1st of each month direct into the Respondents account"

Contrary to the order I have increased the payments each year inline with the CMS calculation upon receiving my P60.

My eldest is 18 and finished secondary education in May. I told my ex that I would be reducing my payments to just cover the youngest child (17) and would give the balance to my eldest to help her through University for as long as I am able (hopefully all the way through).

My ex has disagreed and said I am bound by the Order to continue paying until we agree differently and she doesn't agree to a change. Previously my ex has tried to insist that child payments are to continue through tertiary education however I have refused as we have already made a fund of £50k available for that. My eldest has already used most of her share to study a baccalaureate diploma in Costa Rica but that's another story!

Not that it makes a difference regarding obligations but I have almost zero contact with my children and haven't seen them in two years - the result of parental alienation.

Do I need to vary the Financial Remedy Order, how do I do it and can I if my Ex wont agree?

Many thanks

Quickest, cheapest and easiest rote would be check what you would pay for one child via CMS. If less than £858.88 apply to them and it will override the court order and have a definite end date.

WY Special, thank you so much, I didn't know this option was available. I have already spoken with them this morning.

If you have a claim via the CMS, then that will end when the child's child benefit will end. Even if you continue with your private (Consent Order ) arrangement, that too will end when CB ends, if the consent order doesn't state specifically that CM will continue through tertiary education.