Motion to Change Child Support in Ontario: 2026 Guide

Quick Answer

Your Support Order Did Not Change, and That Is Not a Mistake

Many Ontario parents have run the federal child support calculator this year and found a number that does not match their court order. If that happened to you, nothing has gone wrong.

The Federal Child Support Tables were updated on October 1, 2025. They apply automatically to new orders. They do not reach back and rewrite orders that already exist. The gap is real, but it is a change you may be able to ask for, not one that has happened to you.

Quick Start: Pick Your Path

Four questions sort most parents into one route.

If your order is final, one parent has the children at least 60% of the time, and support is the only change you want, start with the Child Support Service. Otherwise, a Motion to Change is your route. See our overview of child support in Ontario.

Why Your Order Did Not Change on Its Own

The tables run a paying parent’s income against current tax rules. Those rules had shifted since 2017, so the amounts were regenerated. Some went up, some went down. What changed, and who now pays more or less, is covered in our guide to what changed in the 2025 Federal Child Support Tables.

The Two Routes to Change a Child Support Order

The routes differ in what each can decide. The Child Support Service applies the current table to the paying parent’s income and produces a number. It cannot decide whether a parent is deliberately earning less than they could.

A Motion to Change can. A judge may impute income to a parent who is intentionally underemployed, rule on section 7 special expenses such as childcare or orthodontics, and change parenting arrangements at the same time.

When the Child Support Service May Be the Faster Route

One parent must have the children at least 60% of the time. The other parent is notified by mail and typically has 25 calendar days to respond online. A copy of the Notice goes automatically to the Family Responsibility Office, which enforces support.

The service cannot recalculate a temporary order, resolve section 7 expense disputes, or decide contested income questions. Where those issues are live, you likely need the court route.

Filing a Motion to Change: The Step-by-Step Roadmap

1. 1
   Gather your documentsA certified copy of the final order, three years of tax returns and Notices of Assessment, and proof of current income.
2. 2
   Complete the formsForm 15 is the Motion to Change and Form 15A is the Change Information Form. Where the amount of support is in issue, add Form 13 or Form 13.1, the Financial Statement.
3. 3
   File and serveThe clerk seals and dates your motion and gives you a court file number. Rule 15 then requires special service: documents are handed to the other parent in person, or to their lawyer. You cannot serve them yourself. Include blank Forms 15B and 15C, and have the server swear Form 6B, the Affidavit of Service.
4. 4
   Wait for the responseThe other parent typically has 30 days, or 60 if served outside Canada or the United States.
5. 5
   Then one of three things happensIf you agree, you file Form 15D, the Consent Motion to Change Child Support, and a judge may make the order without either of you attending. If they file Form 15B, the Response to Motion to Change, your case moves to a case conference. If they do nothing, the motion may proceed unopposed.

Our guide to filing family court documents online in Ontario explains the portals.

What Counts as a Material Change in Circumstances

Other qualifying changes typically include a child finishing school, moving in with the other parent, or parenting time crossing the 40% threshold that triggers a different calculation.

Whether the 2025 table update on its own is enough is harder. Justice Canada’s position is that where the updated amount differs from an existing order, that difference could be considered a change in circumstances allowing either parent to apply. That is permission to ask, not a promise of any result. A court decides on the facts.

As Qasim Ali, Principal Lawyer at Nihang Law, often tells clients, the table look-up is the easy part. Establishing income, particularly for a self-employed parent, is where these files are decided.

Which Tables Apply to Which Time Period

The updated tables do not reach backwards simply because they exist. A judge may order a change effective from a past date, but that depends on the facts.

What a Motion to Change Costs and How Long It Takes

Cost depends on where your case is heard. There are no filing or listing fees in family proceedings at the Ontario Court of Justice. Fees may apply in the Superior Court of Justice depending on the subject matter, and court fees change over time, so check the Government of Ontario’s family court fees page for current amounts. A fee waiver may be available. The Child Support Service charges $80 per parent.

Timelines vary. A motion on consent may be decided without a court appearance. A contested motion goes to a case conference first and can take considerably longer.

Common Mistakes to Avoid

• Assuming the new tables changed your order automatically. Payments continue at the old amount until someone applies.
• Skipping the Child Support Service. Many parents qualify for the online route and never find out.
• Reducing payments before the order is changed. The order stays enforceable until varied, and paying less creates arrears.
• Filing with incomplete disclosure. Missing tax returns and Notices of Assessment are a common reason a motion stalls.
• Confusing Form 15C with Form 15D. Form 15C is the general consent form. Form 15D is for child support only.
• Treating a $0 table amount as the end of the obligation. A parent earning at or below $16,000 has a basic table amount of $0, but section 7 expenses may still apply and a court may impute income. See our guide to how child support is calculated in Ontario.

Frequently Asked Questions

Getting Help With Your Motion to Change

The 2025 tables do not touch your existing order. Nothing changes until a parent asks, so you have time to run the numbers, talk to your co-parent, and choose the route that fits.

Nihang Law serves Toronto, Scarborough, and the GTA in multiple languages. To talk through which route applies to your order, contact our family law team.

About the author

Qasim Ali

Principal Lawyer · Nihang Law Professional Corporation · Toronto & Scarborough, Ontario · Law Society of Ontario

Qasim Ali is the Principal Lawyer at Nihang Law Professional Corporation, serving clients across Toronto, Scarborough, and the broader Greater Toronto Area. He provides full-service legal representation across immigration, real estate, family law, criminal law, civil litigation, employment law, wills and estates, and business law.

Nihang Law is particularly recognized for its depth in immigration and real estate law, a combination that serves newcomers and growing families navigating both legal systems simultaneously.

Learn more about Qasim Ali →

Sources & References

• Justice Canada — 2025 Update to the Federal Child Support Tables
• Justice Canada — Frequently Asked Questions, 2025 Update to the Federal Child Support Tables
• Justice Canada — 2025 child support table look-up
• Canada Gazette, Part II — SOR/2025-166, Regulations Amending the Federal Child Support Guidelines
• Federal Child Support Guidelines, SOR/97-175 (section 14)
• Government of Ontario — Set up or update child support online
• O. Reg. 114/99 — Family Law Rules, Rule 15
• Ontario Court of Justice — Motions
• Government of Ontario — Family court fees