Your RRSP contribution limit isn't just 18% of last year's income

Your RRSP contribution limit for 2025 is $32,490 — unless you've got unused room from previous years. Then it could be much higher.

Most Canadians think the limit is just 18% of last year's earned income, up to the annual maximum. That's only half the formula. The CRA adds any unused contribution room you've accumulated since 1991, when the system started tracking carry-forwards.

If you earned $70,000 last year but only contributed $8,000 to your RRSP, you've got $4,600 in unused room ($12,600 minus $8,000) that carries forward indefinitely. Next year, that unused room gets added to your new 18% allowance.

How the math actually works

Your RRSP contribution limit has two parts:

1. New room: 18% of last year's earned income, up to the annual maximum ($32,490 for 2025)
2. Unused room: Any contribution space you didn't use in previous years

The CRA tracks your unused room automatically. If you contributed $20,000 in 2024 but your limit was $28,000, you've got $8,000 in carry-forward room for 2025.

Here's where it gets specific to your situation: if you're in a workplace pension plan, your RRSP room gets reduced by something called a pension adjustment (PA). You'll find this number on your T4 slip — it's how the CRA makes sure you're not double-dipping on tax-deferred retirement savings.

At $80,000 income in Ontario, maxing out your RRSP saves roughly $3,600 in taxes. But that only works if you actually have the room to contribute the full amount. TaxSplit.ca shows you the exact refund based on your province and income level.

Where to find your actual limit

Your Notice of Assessment has your real contribution limit — the one that includes carry-forward room. It's in the "RRSP/PRPP deduction limit" section, not the generic annual maximum everyone talks about.

You can also log into your CRA My Account online. The RRSP section shows your available contribution room updated to reflect any contributions you've already made this year.

The phone line (1-800-267-6999) works too, but you'll need your SIN and previous year's tax info ready.

The over-contribution penalty nobody mentions

The CRA gives you a $2,000 buffer above your limit before penalties kick in. Go over by $2,001 or more, and you're paying 1% per month on the excess amount until you withdraw it.

That buffer isn't extra contribution room — it's protection against small calculation errors. Don't treat it as part of your actual limit.

What happens at 71

You can contribute to your RRSP until December 31 of the year you turn 71. After that, the account has to be converted to a RRIF, used to buy an annuity, or cashed out.

If you're contributing to a spousal RRSP, the age limit follows your spouse's birthday, not yours.

The carry-forward room doesn't disappear when you hit the age limit. If you've got unused room at 71, it's gone — another reason to stay on top of your actual contribution space rather than assuming it's just this year's 18%.

Your RRSP limit is probably higher than you think. The question is whether you've been tracking the right number.