What does the Quebec model actually calculate?

It considers both parents' disposable income, the number of children, the custody time split between parents, and additional child-specific expenses (like childcare or special needs costs) beyond a basic amount. Both parents complete a Child Support Determination Form (Annex 1) with their financial information, and the government provides an online calculation tool to help work through the formula.

What is SARPA and how is it different from going to court?

SARPA (Service administratif de rajustement des pensions alimentaires pour enfants) is an administrative service that lets a parent adjust an existing child support amount, when there's been a change in income or circumstances, without appearing before a judge. It only works if the current amount was already set by a judgment, applies to children under 18, and requires both parents to reside in Quebec. It costs $57.25 (indexed annually), free for parents who qualify for legal aid, and typically takes three to six months to process.

Can SARPA set an initial support order, or only adjust an existing one?

Only adjust an existing one. SARPA requires that child support was already set by a judgment, it's a recalculation tool for a change in circumstances, not a way to get a first support order. An initial order still needs to go through the court, or through the Homologation Assistance Service if both parents already agree on an amount.

What if both parents agree on a change but don't want SARPA?

The Homologation Assistance Service (Service d'aide à l'homologation, HAS) lets parents who agree on changes to custody, access, or support, get that agreement turned into a new judgment through a legal aid office, without a fully contested hearing. It costs $325.50 per parent (indexed annually), free for legal aid-eligible parents, and can address more than SARPA can, including custody and access changes alongside support.

How is child support enforced in Quebec?

Quebec's automatic support payment collection system, administered through Revenu Québec, withholds support directly from the paying parent's income in most cases and forwards it to the receiving parent, similar in principle to income withholding used elsewhere in Canada. Parents with concerns about non-payment should contact Revenu Québec's support payment service or consult a family law lawyer or notary about further enforcement steps.

Quebec, Canada

Quebec Child Support: A Parent's Guide

Q: Does Quebec use the Federal Child Support Guidelines table like the rest of Canada?

No. This is one of the most distinctive things about Quebec family law: every other Canadian province and territory calculates child support using the Federal Child Support Guidelines lookup tables. Quebec has its own formula, the Modèle québécois de fixation des pensions alimentaires pour enfants (Quebec child support determination model), which applies even in divorces governed by the federal Divorce Act, because the Divorce Act allows provinces with their own comprehensive guidelines to use them instead of the federal table, and Quebec is the only province that does.

How child support works in Quebec, in plain English: the distinct Quebec determination model, SARPA for adjusting support without court, and how to apply, vary, and enforce an order.

Legal sources reviewed: August 11, 2026

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In short: Quebec is the only Canadian province that doesn't use the Federal Child Support Guidelines table. It has its own formula, the Quebec child support determination model, which weighs both parents' income, the custody time split, and the child's specific needs. For adjusting an existing support amount after a change in circumstances, Quebec also offers SARPA, an administrative service that skips the courtroom entirely.

This is an educational overview written for parents, not lawyers. It isn't legal advice. For anything beyond general understanding, talk to a licensed Quebec family law lawyer or notary, or use the resources at Québec.ca: Separation and Divorce.

The Quebec child support determination model

Every other Canadian province and territory calculates child support using the Federal Child Support Guidelines, a national lookup table based primarily on the paying parent's income and the number of children. Quebec is different. Because the federal Divorce Act permits a province to apply its own comprehensive support guidelines instead of the federal table when that province has established one, Quebec applies its own: the Modèle québécois de fixation des pensions alimentaires pour enfants (Quebec child support determination model). This applies to Quebec families whether the case is a federal divorce or a Civil Code separation.

Rather than a simple lookup by income and number of children, the Quebec model factors in:

Both parents' disposable income, not just the paying parent's
The custody time split, how the child's time actually divides between the two homes
The number of children
Additional child-specific expenses, such as childcare, special needs, or extraordinary education costs, on top of the basic contribution

Parents work through this using the Child Support Determination Form (also called Annex 1), which captures both parents' financial information and produces the support figure. Quebec's government provides an online calculation tool to help complete the form, along with a published guide explaining the model with worked examples. In a shared custody situation where time is split evenly, the annual support contribution is generally divided into two equal shares based on each parent's relative income.

Because the model directly incorporates the actual custody split rather than a rough joint-custody adjustment, changes to the parenting schedule can move the support number just as much as a change in either parent's income, worth keeping in mind if your schedule shifts.

SARPA: adjusting support without going to court

SARPA (Service administratif de rajustement des pensions alimentaires pour enfants) is a genuinely distinctive piece of Quebec's system: an administrative service, not a court process, for adjusting an existing child support amount when circumstances have changed.

What SARPA can do:

Recalculate the child support amount using the Quebec model, applied to updated income figures
Process the change without either parent appearing before a judge

Eligibility:

Both parents must reside in Quebec
The current support amount must already have been set by a judgment (SARPA adjusts existing orders, it doesn't create a first order)
There's a change in financial circumstances or the child's situation that justifies recalculation
The child is under 18

Cost and timeline: $57.25 (indexed annually), free for parents who qualify for legal aid. Processing generally takes three to six months. Generally, one parent can initiate a SARPA request without the other's agreement, though certain situations require both parents' consent.

If both parents agree on a change and want to address more than just the support number, custody or access changes alongside support, the Homologation Assistance Service (Service d'aide à l'homologation, HAS) is the broader option: $325.50 per parent (indexed annually, free for legal aid-eligible parents), arranged through a legal aid office, resulting in a new judgment reflecting the parents' agreement.

Applying, varying, and enforcing support

Getting an initial order: A first child support order comes from the court (as part of a divorce or separation proceeding) or, if both parents already agree on the amount, through the Homologation Assistance Service.

Varying an existing order: Use SARPA for an income-driven recalculation without court, the Homologation Assistance Service if both parents agree on a broader change, or return to court if there's a dispute that needs a judge's decision.

Enforcement: Quebec collects and enforces child support through an automatic payment collection system administered by Revenu Québec, which withholds support from the paying parent's income in most cases and forwards it to the receiving parent. This operates similarly in principle to income-withholding systems used in other provinces and in US states, though administered through Quebec's own revenue agency rather than a separate child-support agency.

Common questions

Does 50/50 custody mean no support is owed? Not necessarily. Because the Quebec model weighs both parents' income alongside the custody split, a significant income gap can still produce a support obligation even with evenly split parenting time.

Can I use SARPA if my support was set outside Quebec? No, SARPA requires that the existing support judgment and both parents' residency be in Quebec.

What if my co-parent isn't paying? Contact Revenu Québec's support payment service to explore your options, or consult a family law lawyer or notary about further enforcement.

Practical considerations

Because the Quebec model ties the support number directly to the actual custody time split, disputes over the day-to-day schedule can effectively become disputes over the support figure too. Keeping an accurate, current record of the actual parenting schedule matters here more than it might in provinces using a simpler table. For the custody and parental authority rules that shape the underlying schedule, see the Quebec custody guide.

Official Quebec and federal resources

FAQ

Questions, answered

This information is provided for educational purposes only and is not legal advice. Family law varies by individual circumstances and may change over time. Consult a qualified attorney or appropriate official resource for advice about your situation.