Ontario parents can modify child support through three pathways: the free Online Child Support Service at ontario.ca, a consent motion when both parents agree, or a contested Motion to Change (Form 15) when they disagree. The filing fee for a Motion to Change in the Superior Court of Justice is $224, though recipients of Ontario Works or ODSP qualify for a complete fee waiver. Under Section 17 of the Divorce Act, R.S.C. 1985, c. 3 and Section 14 of the Federal Child Support Guidelines, courts will approve modifications when a material change in circumstances has occurred, including significant income changes, shifts in parenting time arrangements crossing the 40% threshold, or the updated October 2025 Federal Child Support Tables producing a different amount than the existing order.
Key Facts: Ontario Child Support Modification
| Factor | Details |
|---|---|
| Filing Fee | $224 (Motion to Change) |
| Fee Waiver | Available for Ontario Works/ODSP recipients |
| Online Service | Free at ontario.ca/childsupport |
| Response Time | 30 days (Canada/US), 60 days (international) |
| Table Update | October 1, 2025 (first revision since 2017) |
| Income Threshold | $16,000 minimum (up from $13,000) |
| Enforcement | Family Responsibility Office (FRO) |
What Qualifies as a Material Change in Circumstances
Ontario courts require proof of a material change in circumstances before modifying child support, as mandated by Section 14 of the Federal Child Support Guidelines. A material change must be substantial, ongoing, and not anticipated when the original order was made. The October 2025 Federal Child Support Table update itself can constitute a material change if the recalculated amount differs significantly from your existing order, providing legal grounds to request a variation without any other circumstantial changes.
Common qualifying changes include:
- Paying parent's income increases or decreases by 10% or more
- Job loss, promotion, or career change affecting annual earnings
- Receiving parent's income changes substantially
- Child's primary residence shifts between households
- Parenting time arrangement crosses the 40% threshold (triggering shared parenting time rules)
- Child turns 18 but remains in full-time education
- Child becomes financially independent or moves out
- Special or extraordinary expenses change significantly (daycare, medical, extracurricular activities)
- Either parent relocates, affecting parenting arrangements
Under Section 17(4) of the Divorce Act, the court must satisfy itself that a change of circumstances has occurred since the making of the original child support order or the last variation order. Courts examine whether the change was foreseeable at the time of the original order, whether it is likely to continue, and whether it materially affects the child support calculation under the Federal Guidelines.
The Three Pathways to Modify Child Support in Ontario
Ontario provides three distinct methods to change child support: the free Online Child Support Service, a consent motion when both parents agree, and a contested Motion to Change when parents disagree. Each pathway has different requirements, timelines, and costs. The online service processes straightforward cases without court appearances, while contested motions may require multiple court dates and take 6-12 months to resolve depending on court backlogs and case complexity.
Option 1: Ontario Online Child Support Service (Free)
The Ontario Online Child Support Service allows parents to set up or update child support without attending court, available at ontario.ca/childsupport. Either the paying or receiving parent can initiate an application through the portal. The service calculates support using the Federal Child Support Guidelines and issues a Notice of Calculation or Recalculation that carries the same legal weight as a court order. A copy is automatically sent to the Family Responsibility Office (FRO) for enforcement.
Eligibility requirements for the online service:
- Both parents must have a valid Social Insurance Number
- The paying parent must have straightforward income (not self-employed or seasonally employed)
- Children must not be in shared parenting time (40% or more with each parent) or split between households
- The matter must not involve complex income calculations
The process works as follows: One parent starts an application and provides income information. The other parent receives a notification letter by mail and has 25 calendar days to respond online with their own income information. If the responding parent fails to respond within 25 days, the service may calculate support based solely on the information provided by the applicant. Both parents then receive a Notice of Calculation or Recalculation by mail, and the new support amount becomes enforceable immediately.
For questions about the online service, parents can call 1-866-656-7753.
Option 2: Consent Motion to Change (Both Parents Agree)
When both parents agree on the child support modification, they can file a Consent Motion to Change using Form 15C (for child support only) or Form 15D. This streamlined process typically requires no court appearance. Lawyers prepare the necessary documentation, obtain judicial approval, and file the new order with the court. The filing fee remains $224 in Superior Court of Justice, but the process is significantly faster and less expensive than a contested hearing because legal fees are minimized.
Required documents for a consent motion:
- Form 15C: Consent Motion to Change Child Support (if only child support is changing)
- Form 15D: Consent Motion to Change (if other matters like parenting arrangements are also changing)
- Updated financial disclosure from both parties
- Copy of the existing order being changed
- Draft of the proposed new order
Option 3: Contested Motion to Change (Parents Disagree)
When parents cannot agree on modifications, the parent seeking the change must file a Motion to Change (Form 15) with the court. This formal court process requires comprehensive financial disclosure, serving documents on the other parent, and potentially attending multiple court appearances. The responding parent has 30 calendar days to file a response (60 days if served outside Canada or the United States). A contested modification typically costs $5,000-$15,000 in legal fees depending on complexity, though self-represented litigants can navigate the process without a lawyer.
How to File a Motion to Change: Step-by-Step Process
Filing a Motion to Change requires careful preparation of multiple court forms and strict compliance with service deadlines. The Ontario Superior Court of Justice charges a $224 filing fee, though parents receiving Ontario Works or Ontario Disability Support Program (ODSP) benefits can apply for a fee waiver that eliminates this cost entirely. Documents can be filed online through Justice Services Online (outside Toronto) or the Ontario Courts Public Portal (Toronto region), or in person at the courthouse.
Step 1: Gather Required Forms and Documents
The moving party (parent requesting the change) must complete and file:
- Form 15: Motion to Change
- Form 15A: Change Information Form
- Form 13: Financial Statement (Support Claims)
- Form 13A: Certificate of Financial Disclosure
- Certified copy of the existing court order being changed
- Proof of current income (most recent pay stub showing year-to-date income)
- Income documentation for the past three taxation years (Notices of Assessment and Reassessment from Canada Revenue Agency)
- If relevant, proof of special or extraordinary expenses (daycare receipts, medical bills, extracurricular activity costs)
- Director's Statement of Arrears from FRO (if support is registered with the Family Responsibility Office)
You must also prepare blank copies of Form 15B (Response to Motion to Change) and Form 15C (Consent Motion to Change) to serve on the other parent.
Step 2: File Documents with the Court
Submit your completed documents to the court for issuance. You can file online at Justice Services Online (for courts outside Toronto) or the Ontario Courts Public Portal (for Toronto region matters), or file in person at the courthouse. If filing in person, you must also prepare a Continuing Record and Table of Contents for the court file. Pay the $224 filing fee or submit a fee waiver application if you receive Ontario Works or ODSP.
Step 3: Serve the Other Parent
After the court issues your documents, you must serve copies on the other parent or caregiver. Service must be completed by someone other than yourself, such as a family member, friend, or professional process server. The server must complete an Affidavit of Service confirming delivery. Service can be completed by personal delivery, registered mail, or courier.
Step 4: Wait for Response
The other parent has 30 calendar days to file a Response to Motion to Change (Form 15B) after being served. If they were served outside Canada or the United States, they have 60 calendar days. If the other parent agrees to the changes, they may file a Consent Motion to Change instead of a response, converting the matter to a consent proceeding.
Step 5: Attend Court Appearances
Depending on the court location and whether the matter settles, you may need to attend:
- Case Conference: A mandatory first court appearance where parties meet with a judge to narrow issues and explore settlement
- Settlement Conference: A follow-up appearance focused on resolving disputed issues
- Motion Hearing or Trial: If the matter cannot be settled, the court will schedule a hearing where both parties present evidence and the judge makes a decision
2026 Federal Child Support Table Changes
The October 1, 2025 update to the Federal Child Support Tables represents the first comprehensive revision since 2017, incorporating 2023 tax rules and current cost-of-living data. These updated tables are the mandatory standard for all new child support orders and agreements in 2026. Existing orders do not automatically update to reflect the new tables; parents must take action through one of the three pathways described above. If the updated table produces a materially different amount from your existing order, that difference qualifies as a change in circumstances under Section 14 of the Guidelines.
Key Changes in the 2026 Tables
| Income Range | 2017 Tables | 2025/2026 Tables | Change |
|---|---|---|---|
| Below $16,000 | Support calculated from $13,000 | Base amount of $0 | Self-support reserve increased |
| $16,000-$45,000 | Higher base amounts | Generally lower amounts | Reflects updated tax rules |
| $45,000-$150,000 | Based on 2017 tax data | Recalculated using 2023 tax rules | Varies by bracket |
| Above $150,000 | Table + Section 4 discretion | Same structure, updated figures | Court discretion applies |
The self-support reserve increased from $13,000 to $16,000, reflecting the updated federal basic personal amount at which tax obligations begin. This means paying parents earning below $16,000 annually now have a base table amount of $0, though special or extraordinary expenses may still apply. For parents in the $16,000-$45,000 income range, the new amounts tend to be lower than under the 2017 tables.
How to Determine If Your Order Should Be Updated
Compare your current order against the 2026 tables using these steps:
- Obtain the paying parent's current gross annual income
- Look up the table amount for that income level using the Federal Child Support Tables for Ontario (available at justice.gc.ca)
- Compare the table amount to your existing court order or agreement
- If the amounts differ significantly, you have grounds for a variation application
Retroactive Child Support Modifications
Ontario courts have authority under Section 17 of the Divorce Act to make variation orders that apply retroactively, though courts generally limit retroactive adjustments to the date the modification application was filed. In DBS v. SRG (2006 SCC 37), the Supreme Court of Canada established that retroactive increases may be ordered when the paying parent failed to disclose income increases or when the receiving parent delayed applying for reasons beyond their control. Retroactive decreases are more difficult to obtain because the paying parent bears responsibility for promptly seeking a variation when circumstances change.
Factors courts consider for retroactive modifications:
- Whether the applicant delayed unreasonably in seeking the variation
- Whether the payor engaged in blameworthy conduct (hiding income, lying about earnings)
- The circumstances of the child at the time
- Any hardship the retroactive award would cause to either party
As a practical matter, parents should apply for a variation as soon as a material change occurs rather than waiting months or years. Courts are skeptical of paying parents who continue at the old rate for extended periods before seeking a reduction, viewing the delay as evidence that the reduction was not truly necessary.
Family Responsibility Office (FRO) and Enforcement
Once a child support order is made or varied, it is automatically filed with the Family Responsibility Office (FRO) for enforcement. FRO collects payments from the paying parent and distributes them to the receiving parent, eliminating direct financial transactions between the parties. Notices of Calculation or Recalculation from the Online Child Support Service are also automatically registered with FRO. Both parents receive access to FRO Online, a secure web portal for tracking payments, viewing account statements, and communicating with enforcement officers.
FRO has significant enforcement powers for non-payment:
- Garnishing wages directly from the employer
- Seizing federal tax refunds and GST/HST credits
- Suspending driver's licenses (with 30 days' notice)
- Suspending passports
- Reporting arrears to credit bureaus
- Bringing the defaulting parent to court for contempt (which may result in fines or imprisonment)
Important limitation: FRO cannot reduce support payments or arrears. Only a court order can modify the amount owed. If you are paying support and your circumstances change, you must apply to court for a variation. Continuing to pay the old amount while a variation application is pending may result in arrears accumulating, but paying less than the ordered amount without court approval will definitely result in enforcement action.
Contact FRO at 1-800-267-4330 (toll-free) or 416-326-1817 (Toronto). The online portal is available at ontario.ca/FROonline.
Cost of Modifying Child Support in Ontario
The total cost of modifying child support depends heavily on whether the modification is contested and whether you use a lawyer. The Online Child Support Service is free for eligible parents. Consent motions cost less than contested proceedings because they require minimal court time and legal work. Contested motions can become expensive if the matter proceeds to a full hearing.
| Modification Type | Court Fees | Typical Legal Fees | Total Estimated Cost |
|---|---|---|---|
| Online Service | $0 | $0 | Free |
| Consent Motion | $224 | $1,500-$3,000 | $1,724-$3,224 |
| Contested Motion | $224 | $5,000-$15,000 | $5,224-$15,224 |
| Self-Represented Contested | $224 | $0 | $224 |
Fee waivers are available for parents receiving Ontario Works or Ontario Disability Support Program (ODSP) benefits. Legal Aid Ontario may provide assistance for low-income parents through duty counsel services or Legal Aid certificates. Community legal clinics also offer free advice on family law matters.
Timeline for Child Support Modifications
The time required to modify child support varies significantly based on the pathway chosen and whether the matter is contested. The Online Child Support Service is the fastest option for eligible parents, while contested court proceedings may take many months depending on court scheduling and case complexity.
| Pathway | Typical Timeline |
|---|---|
| Online Child Support Service | 4-8 weeks |
| Consent Motion | 6-12 weeks |
| Contested Motion (Simple) | 4-6 months |
| Contested Motion (Complex) | 8-12 months |
Factors that extend timelines include incomplete financial disclosure, disputes over income (especially self-employment or business income), parenting arrangement disputes that must be resolved before support is calculated, and general court backlogs. The Toronto region often has longer wait times than smaller court locations.
Special Situations
Shared Parenting Time (40% or More with Each Parent)
When children spend 40% or more of their time with each parent, Ontario uses the shared parenting time calculation under Section 9 of the Federal Child Support Guidelines. The offset method calculates what each parent would pay the other under the tables, then offsets the amounts. The parent with higher income pays the difference. Variations in shared parenting time that cross the 40% threshold can significantly change support obligations and constitute a material change in circumstances.
Self-Employed Paying Parents
When the paying parent is self-employed, courts examine business income carefully to determine the appropriate income for Guidelines purposes. Business expenses may be adjusted or disallowed if they reduce income unreasonably. Self-employed parents cannot use the Online Child Support Service and must proceed through court. Financial disclosure requirements are more extensive, including business financial statements, corporate tax returns, and accountant reports.
High-Income Parents (Above $150,000)
For paying parents earning above $150,000 annually, Section 4 of the Federal Child Support Guidelines provides judicial discretion. The table amount for the first $150,000 is mandatory. For income above $150,000, the court may order the table amount, a lesser amount, or a greater amount based on the child's actual needs and the family's pre-separation standard of living. Courts examine the child's historical expenditures and lifestyle to determine appropriate support above the threshold.
How to Calculate Your Potential New Support Amount
Before filing for a variation, calculate the potential new support amount to determine whether the change is significant enough to warrant the process. Use the Federal Child Support Tables for Ontario (available at justice.gc.ca or through online calculators). Input the paying parent's current gross annual income and the number of children to find the monthly base table amount. Compare this to your existing order.
Example calculation:
- Paying parent's 2026 gross annual income: $85,000
- Number of children: 2
- 2026 Ontario table amount: $1,245 per month
- Current court order (based on 2017 tables and $75,000 income): $1,089 per month
- Difference: $156 per month increase
This $156 monthly difference ($1,872 annually) would likely qualify as a material change in circumstances warranting a variation application.
Frequently Asked Questions
How much does it cost to file a Motion to Change child support in Ontario?
The filing fee for a Motion to Change in Ontario Superior Court of Justice is $224 as of May 2026. Parents receiving Ontario Works or Ontario Disability Support Program (ODSP) benefits can apply for a fee waiver that eliminates this cost entirely. The Ontario Court of Justice has no filing fees for family matters. Legal fees for a contested motion typically range from $5,000-$15,000 depending on complexity.
Can I modify child support without going to court in Ontario?
Yes, Ontario's Online Child Support Service allows eligible parents to set up or update child support without attending court. Either parent can start an application at ontario.ca/childsupport. However, the service cannot be used for shared parenting time arrangements, split custody, or when the paying parent has complex income such as self-employment. Parents who agree on changes can also file a consent motion that typically requires no court appearance.
How long does it take to change a child support order in Ontario?
The timeline varies by pathway: the Online Child Support Service takes 4-8 weeks, consent motions take 6-12 weeks, and contested motions take 4-12 months depending on complexity and court backlogs. The other parent has 30 days to respond to a Motion to Change (60 days if served outside Canada or the United States). Case conferences and settlement conferences may be required before a final hearing is scheduled.
What qualifies as a material change in circumstances for child support?
A material change must be substantial, ongoing, and not anticipated when the original order was made. Common qualifying changes include: significant income changes (10% or more), job loss or promotion, parenting time crossing the 40% threshold, a child turning 18 while in full-time education, changes in special expenses, or the October 2025 Federal Child Support Table update producing a different amount than your existing order.
Do the 2026 child support tables automatically update my existing order?
No, existing orders do not automatically update. If your court order predates October 1, 2025, it remains at the original amount until you take action to change it. However, if the updated tables produce a materially different amount, that difference qualifies as a change in circumstances under Section 14 of the Federal Child Support Guidelines, giving either parent legal grounds to apply for a recalculation or variation.
Can child support be reduced if I lose my job?
Yes, job loss is a recognized material change in circumstances that can justify reducing child support. However, you must apply to court promptly, as reductions are rarely granted retroactively for periods before the application was filed. Courts will examine whether the job loss was voluntary, whether you are making reasonable efforts to find new employment, and your potential earning capacity. Voluntarily reducing income to avoid support obligations will not succeed.
What happens if I just stop paying because my income dropped?
Unilaterally reducing or stopping payments without a court order is not permitted and will result in enforcement action by the Family Responsibility Office. Arrears will accumulate at the ordered rate, and FRO can garnish wages, seize tax refunds, suspend licenses, and bring you to court for contempt. You must continue paying the ordered amount while a variation application is pending unless the court grants interim relief.
How do I prove my income changed for a child support modification?
You must provide Form 13: Financial Statement (Support Claims) along with supporting documentation including: your most recent pay stub showing year-to-date income, Notices of Assessment and Reassessment from CRA for the past three taxation years, any termination or severance documentation, employment insurance records, social assistance statements, or pension stubs. Self-employed individuals must provide business financial statements and tax returns.
Can the receiving parent request an increase in child support?
Yes, either parent can apply to modify child support when circumstances change. Receiving parents commonly request increases when the paying parent's income rises, when special or extraordinary expenses increase, or when the 2026 tables produce higher amounts than the existing order. The process and requirements are identical whether seeking an increase or decrease.
What if the other parent lives in a different province or country?
Inter-jurisdictional child support matters are handled under the Inter-jurisdictional Support Orders Act. If the responding parent lives in another Canadian province or territory, the application can proceed through reciprocal enforcement agreements. Ontario has enforcement agreements with every Canadian province and territory, the United States, and several other countries. The responding parent has 60 days to respond (instead of 30) when served outside Canada or the United States.
As of May 2026. Filing fees and procedures may change. Verify current requirements with the Ontario Superior Court of Justice or visit ontario.ca/familycourt.