Calculating spousal and child support in Ontario: what changed in 2025

If you pay or receive support in Ontario, one change from 2025 actually matters: the federal child support tables were updated for the first time since 2017, with new amounts in effect since October 1, 2025. Here is what changed, what did not, and what to check if your order was made under the old tables.

Child support in Ontario is set under the Federal Child Support Guidelines. The basic monthly amount comes from a table based on the paying parent’s gross annual income, the number of children, and the province where the payor lives. In 2025 the federal government updated those tables to reflect current tax rules, the first update since November 2017.

The new tables apply to support owed from October 1, 2025 onward. Support owed for any period between November 22, 2017 and September 30, 2025 is still calculated under the 2017 tables.

If your order or separation agreement predates October 1, 2025, the amount does not change automatically. But if the new table amount differs meaningfully from what you currently pay or receive, that difference can amount to a change in circumstances, which is the legal basis for asking the court to vary the order. Whether it is worth doing depends on the size of the gap, so run the numbers before you file anything. Our child support calculator gives the current Ontario table amount for a given income.

The table only works if the income going into it is right. Where a parent is self-employed, paid partly in cash, or earning less than they reasonably could, section 19 of the Guidelines lets the court impute income and calculate support on what that parent should be earning rather than what they declare. Judges use this power regularly. If you suspect the other side’s income is understated, raise it early and back it up with disclosure requests.

Section 19 lists the situations where a court can attribute income to a parent. The ones that come up most:

• Intentional under-employment or unemployment. A parent who quits a good job or works part time by choice can be treated as earning what they could earn. There are carve-outs where the reduced work is required by the needs of a child or by the parent’s own reasonable education or health needs.
• Income that does not show up on paper. Cash earnings, income diverted through a corporation, or property sitting idle that could reasonably produce income.
• Unreasonable deductions. Self-employed parents sometimes write off personal costs as business expenses. The tax return may satisfy the CRA and still overstate the deductions for support purposes, so the court adds them back.
• Refusing to disclose. A parent who will not produce income information when legally required to can have income imputed against them. Silence is not a shield.

Support is not only about next month. Courts can order retroactive support for periods when a parent paid less than the Guidelines required. The framework comes from the Supreme Court of Canada’s 2006 decision in D.B.S. v. S.R.G.: the award generally reaches back to the date the recipient gave the payor effective notice that support needed to be sorted out, usually to a maximum of three years before that notice. Effective notice does not mean a court filing. Raising the topic clearly can be enough.

The three-year marker is a guideline, not a wall. Where the payor behaved badly, hiding a raise, understating income, or stalling, courts go back further. And in Michel v. Graydon (2020), the Supreme Court allowed a parent to go back and correct support under an old order based on income the payor had understated, even though the child was an adult by the time she applied. The message from both cases is the same: underpaying and waiting out the clock is not a strategy that ends well.

If your income has genuinely dropped, or the children’s circumstances have shifted, the route is a motion to change under the Family Law Rules. You need a material change in circumstances, meaning a real and lasting difference from the situation the original order was built on: a job loss, a serious illness, a child moving in with the other parent. The 2025 table update can itself be that change, as covered above.

What you should not do is strike an informal side deal and leave the order alone. A handshake reduction does not bind the court, arrears keep accruing under the order as written, and years later you can be facing a bill for the difference with interest. If you both agree to a new amount, put it in a consent order or a proper agreement so the paper matches reality.

One more reason paperwork matters: Ontario support orders are enforced by the Family Responsibility Office, which collects the amount in the order, not the amount you privately agreed to. FRO can garnish wages and bank accounts, intercept tax refunds, and suspend a driver’s licence over arrears. Until the order changes, the old number is the one being enforced.

The Spousal Support Advisory Guidelines were not rewritten in 2025. They remain advisory rather than binding, and the current framework is still the 2008 guidelines together with the 2016 Revised User’s Guide. Ontario courts treat the SSAG ranges as the starting point in most cases.

There is a knock-on effect, though. Where child support is also being paid, the SSAG formula works out spousal support after child support comes off the top. New table amounts can shift the spousal support range even though the spousal guidelines themselves did not change.

Three practical points

Disclose everything. Full financial disclosure of income, assets, and debts is mandatory. Incomplete disclosure delays your case, and an agreement built on bad numbers can be set aside later.

Mind the tax treatment. Child support is not taxable in the recipient’s hands and not deductible for the payer. Monthly spousal support paid under a court order or written agreement runs the other way: deductible for the payer, taxable for the recipient. The after-tax picture should shape any deal you sign.

Get advice before you sign. Support agreements negotiated without the current tables and ranges in front of you tend to be unfair to someone. A family lawyer can tell you what your entitlements and obligations actually are before you commit to anything.

If you have questions about child or spousal support, contact us for a consultation. We will tell you where you stand and whether the 2025 tables change anything for you.

• For families
• Rule changes
• Ontario courts

This article is general information, not legal advice, and does not create a solicitor-client relationship. It is current as at its publication date and is not revised as the law changes. For advice on your specific situation, book a consultation or call 416-639-0887.

Written by

Caleesis Telesh

Founder & Principal Lawyer

LL.B. · B.A., York University · Member, Law Society of Ontario

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