Quebec operates its own parallel system for both child support and provincial taxation, creating several differences that directly affect support calculations. The province uses a dual-income "disposable income" model for child support (Form 1) rather than the federal payor-only gross income tables, has its own pension plan (QPP) and parental insurance (QPIP), and receives a 16.5% federal tax abatement. These differences compound through the NDI waterfall and can produce materially different support outcomes than the same incomes would generate in any other province.

Form 1: The Quebec Child Support Model

Outside Quebec, child support is based solely on the payor's gross income — the recipient's income is irrelevant to the table lookup. Quebec's Form 1 model works differently: it calculates each parent's "disposable income" (income after taxes and certain deductions), combines them, and determines each parent's proportional share of the children's costs. This means both parents' incomes matter for child support in Quebec.

The Quebec model also recognizes an access time adjustment for parenting time between 20% and 40% — a range the federal guidelines do not recognize (the federal 40% threshold is a strict cutoff). And Quebec treats expenses like extracurricular activities more broadly than the federal Section 7 framework, with different rules for what qualifies and how costs are shared.

QPP vs CPP

Quebec residents contribute to the Quebec Pension Plan (QPP) rather than the Canada Pension Plan (CPP). The QPP base rate is 5.40% (2025), compared to CPP's 4.95%. Both share the same Year's Maximum Pensionable Earnings ($71,300 in 2025) and the enhanced second tier (QPP2/CPP2 at 4% on earnings between $71,300 and $81,200). The higher QPP rate means Quebec residents pay slightly more in pension contributions, which reduces their after-tax income and NDI.

QPIP and Lower EI

Quebec administers its own parental insurance through the Quebec Parental Insurance Plan (QPIP), which replaces the parental benefits component of federal EI. In exchange, Quebec residents pay a lower EI rate (1.31% in 2025 vs 1.64% for other provinces) plus a separate QPIP premium (0.494% in 2025 on insurable earnings up to $98,000). The net effect is roughly similar in dollar terms, but the mechanics differ in the tax calculation.

The 16.5% Federal Abatement

Because Quebec collects its own provincial income tax independently (unlike all other provinces, where the CRA collects both federal and provincial tax), Quebec residents receive a 16.5% abatement on their federal tax payable under ITA s.120(2). This substantially reduces the federal portion of their tax bill — but Quebec's own provincial tax rates are higher than most other provinces to compensate. The net effect on NDI depends on the income level and the specific Quebec tax brackets.

Quebec Benefits

Quebec has its own income-tested benefits that enter the NDI waterfall, administered by Retraite Québec and Revenu Québec rather than the CRA:

SSAG Chapter 15: Spousal Support in Quebec

Because Quebec's child support amounts are calculated differently from the federal tables, the SSAG with-child formula cannot use the federal child support figure as its starting point. Chapter 15 of the SSAG addresses this by adjusting the INDI calculation to account for the different child support base. The effect is that spousal support amounts for Quebec cases may differ from what the same incomes would produce under the standard with-child or without-child formula using federal table amounts.