Child Support in Quebec: How to Calculate, Request, Contest and Enforce

In Quebec, child support is calculated according to a precise model that takes into account the income of both parents, the number of children, the type of custody and special expenses. This guide walks you through every step: understanding the calculation, completing the mandatory forms, filing a request with the court or by agreement, modifying an existing amount through SARPA, and having payments enforced by Revenu Québec if the other parent does not pay. You will also find ways to use artificial intelligence to better understand your situation and prepare your documents.

How the Amount of Child Support is Calculated

In Quebec, the amount of child support is not left to chance. It is determined by the Quebec Child Support Determination Model, a formula governed by law that takes into account four main factors: the disposable income of each parent, the number of children, the type of custody (sole, shared or mixed), and certain special expenses such as childcare costs, private school fees or extracurricular activities.

Disposable income is your gross income from all sources minus certain deductions provided by law. The income of both parents is added together to obtain the combined income, then the official determination table indicates the base amount based on this combined income and the number of children. Each parent then contributes in proportion to their share of the total income.

An important point that many people overlook: child support has been tax-neutral since 1997. This means that the parent who receives it does not pay tax on it, and the parent who pays it cannot deduct it.

💡 AI Tip: You can copy and paste your income and family situation into an AI assistant like Gemini and ask it to estimate your child support according to the Quebec determination table. The AI can also explain each line of the form in plain language. Always verify the result with the official government tool.

The Official Government Calculation Tool

The Quebec government offers a free online calculation tool that performs the calculations automatically. You enter your income, the type of custody and the expenses, and the tool produces a printable result. It is an excellent starting point to understand what to expect.

However, this result does not replace the Child Support Determination Form (Schedule I), which is the official document required by the court. You must complete this form for any request filed with the court.

Each parent must also complete a Declaration Required Under Section 444 of the Code of Civil Procedure, a document that details your income, assets and debts. To help you complete the form, the government offers a complete guide with examples (PDF).

How to Request Child Support

If you agree with the other parent: you can submit an agreement to the court for homologation. Both parents complete the determination form together and file it with the agreement. The judge will verify that the amount sufficiently covers the children's needs. The parents must then complete Part 7 of the form (Agreement Between Parents) and clearly state the reasons for any deviation from the amount provided by the table.

If you do not agree: you must file a request with the competent court. Since the family law reform and the creation of the Unified Family Court (UFC) in effect since June 30, 2025, jurisdiction depends on your situation: married couples (divorce) still fall under the Superior Court, while common-law partners subject to the new parental union regime fall under the Court of Quebec (UFC). In all cases, the determination form must accompany the request, failing which it will be rejected.

Before going to court: you are entitled to 5 hours of free family mediation funded by the government. An accredited mediator helps you reach an agreement on support, custody and division of assets. This step can save you months of proceedings and thousands of dollars in legal fees.

How to Modify Existing Child Support

Your financial situation has changed — you lost your job, received a promotion, or custody has been modified. You can request a review of child support. Two options are available to you.

Option 1 — SARPA (without court)

The Administrative Service for the Adjustment of Child Support Payments (SARPA) allows you to modify support without returning before a judge. The cost is approximately $57.25 (indexed annually), and it is free if you are eligible for legal aid. The request is made online and processing takes approximately 3 to 6 months. You can make the request alone or jointly with the other parent. Conditions: both parents must reside in Quebec, support must have been set by an existing judgment, and there must be a change in circumstances justifying the review.

Option 2 — Returning to Court

SARPA can adjust support in situations that do not require judicial assessment. Certain situations or types of income may make the file ineligible for SARPA, or require an agreement between the parents on certain elements. In these cases, you must file a modification request with the court. Legal aid offices also offer the Homologation Assistance Service (HAS) to modify a judgment at low cost.

What to Do if the Other Parent Does Not Pay

In Quebec, child support set by judgment is generally collected and redistributed by Revenu Québec under the Support Payment Collection Program. Revenu Québec usually pays amounts to the recipient twice a month (on the 1st and 16th) and can use various collection mechanisms (withholding, payment order, etc.).

In the event of default, Revenu Québec can undertake collection proceedings, including wage garnishment, bank account seizure, tax refund seizure, registration of a legal hypothec on the debtor's property, and in some cases suspension of the driver's licence.

If you are not receiving payments, you generally do not need to take any action yourself. Revenu Québec detects the absence of payment and initiates collection proceedings.

Child Support for an Adult Child

The support obligation does not automatically end at age 18. If your adult child is a full-time student or is unable to provide for their own subsistence, support can continue. Since 2004, a parent who partially supports an adult child can exercise a support claim on their behalf. The court will assess whether the child is making reasonable efforts to become self-sufficient.

Since June 15, 2012, it has been possible to claim support for a child for needs that existed up to three years before the request. If you delayed making your request, you may be entitled to a retroactive amount.

Spousal Support Between Former Spouses

Distinct from child support, spousal support can be granted upon divorce if one spouse is unable to provide for their own needs. The criteria include the duration of the marriage, the roles assumed during the marriage (a spouse stopped working to care for the children), the ability of each spouse to become self-sufficient, and the financial situation of both parties.

Unlike child support, spousal support is taxable for the recipient and deductible for the payer. There is no automatic determination table — the amount is determined by the court according to the circumstances.

Important note: common-law partners are still not entitled to spousal support in Quebec. However, since June 30, 2025, common-law partners who have a child in common are automatically subject to the new parental union regime, which grants them new financial protections upon separation, such as the sharing of the family residence, furniture and vehicles, as well as the possibility of claiming a compensatory allowance.

Using Artificial Intelligence to Understand Your Situation

AI can considerably simplify your child support proceedings. Here are some concrete uses:

Understanding the form: Ask an AI assistant like Gemini to explain each line of the determination form in plain language. Download the PDF form and ask it to guide you step by step.

Estimating your support: Copy the determination table and ask the AI to calculate your estimated contribution based on your income and number of children. The AI can also show you different scenarios (sole vs shared custody) to understand the financial impact of each option.

Understanding a judgment: If you have received a judgment and do not understand certain terms, copy the text into the AI and ask for an explanation in plain language.

Preparing your arguments: If you need to contest an amount or request a modification, the AI can help you structure your arguments by identifying the factors that work in your favour under the law.

⚠️ Important warning: AI can make mistakes. Always verify amounts with the official government calculation tool and deadlines with the court registry. Never rely on AI for a deadline or critical fact without verification.

Official Sources and Resources

📌 Quebec Child Support Determination Model — Québec.ca

📌 Free Online Calculation Tool — Québec.ca

📌 Determination Tables 2024-2025-2026 — Québec.ca

📌 Determination Form Schedule I (PDF) — Québec.ca

📌 Complete Guide with Examples (PDF) — Québec.ca

📌 SARPA — Modify Support Without Court

📌 Support Payment Collection Program — Revenu Québec

📌 Child Support — Éducaloi

📌 JuridiQC — How to Calculate Child Support

📌 Modify Custody and Child Support — Québec.ca

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Other Guides from Justice-Quebec.ca

➡️ Shared Custody in Quebec — Your Rights and How to Prepare Your Case

➡️ Divorce in Quebec — Steps, Costs and Options

➡️ Self-Representation in Court — The Complete Guide

➡️ Filing a Complaint Against a Lawyer

➡️ Legal Aid — Eligibility and Process

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This guide does not constitute legal advice. The information is provided for informational purposes only and is based on the official sources cited. Always verify deadlines and amounts with official sources or the registry of the relevant courthouse. The author of this site is not a lawyer.