The Canada Revenue Agency confirmed this week that the prescribed rate will hold at 3% for the third quarter of 2026, extending a run that started in the third quarter of 2025. Five consecutive quarters at the same level has not happened since the rate first began climbing off its 2020 to 2022 floor of 1%.
The rate that matters for planning purposes right now is not this one. It is the rate for the fourth quarter, which has not yet been set.
How the Fourth Quarter Rate Actually Gets Built
Under section 4301 of the Income Tax Regulations, the prescribed rate is the simple average of three month Government of Canada Treasury bill auction yields from the first month of the preceding quarter, rounded up to the next whole percentage point. For the fourth quarter of 2026, that means the September auctions. Those auctions have not happened yet, so the Q4 rate is genuinely unknown, not merely unannounced.
What is known is the direction of travel across the Canadian yield curve. The Government of Canada 10-year yield closed Tuesday at 3.75%, its highest level since May 2024, up from 3.65% a week earlier. The move has tracked the same Strait of Hormuz volatility driving this week's energy and gold prices. Three-month Treasury bill yields sit at the short end of the curve and respond more to Bank of Canada policy expectations than to long bond moves, but a curve that is rising broadly makes a Q4 increase from 3% a live possibility rather than a formality.
Why the Timing Matters for a Prescribed Rate Loan
A prescribed rate loan used for income splitting with a spouse, common-law partner, or family trust locks in the rate in effect at the time the loan is made. That rate then applies for the life of the loan, provided the borrower pays the required interest to the lender by January 30 of the following year. A loan set up in September at 3% keeps that rate for as long as the loan exists, even if the prescribed rate rises to 4% or higher in subsequent quarters.
For clients considering this structure, the practical planning window is now through the end of September, before the Q4 rate is announced and before any increase would apply to a newly established loan. The lower the prescribed rate at inception, the smaller the return the borrowed funds need to generate before the arrangement produces a net tax benefit for the family.
The quarterly pattern makes the current window visible at a glance.
The rate is set quarterly from the average yield on three-month Government of Canada Treasury bills auctioned in the first month of the preceding quarter, rounded up to the next whole percentage point.
The Other Side of the Yield Move: Renewals
Rising Government of Canada yields do not only affect prescribed rate planning. Five-year fixed mortgage rates are priced directly off the five-year GoC bond yield, which has climbed alongside the 10-year, trading near 3.18% to 3.23% through the first weeks of August. The lowest insured five-year fixed rate available through Ratehub sits near 3.94%, up from levels that would have been unthinkable to homeowners who locked in mortgages during 2020 and 2021.
Roughly a third of Canadian mortgage holders are projected to face higher monthly payments by the end of 2026 as their terms come up for renewal. Three quarters of that group hold five year fixed mortgages, and the average payment increase for borrowers renewing this year is close to 20%, a direct reflection of the gap between pandemic era fixed rates and where five year GoC yields sit today. Variable rate holders are largely insulated from this particular pressure since the Bank of Canada has held its overnight rate at 2.25% for six consecutive meetings.
Two Planning Conversations, One Underlying Cause
Both threads trace back to the same yield move. Clients weighing a prescribed rate loan have a reason to act before the September auctions reset the calculation. Clients approaching a mortgage renewal, particularly on RRSP-linked home purchases or FHSA-funded down payments where cash flow planning already stretches tight, are facing a renewal environment shaped by the same climb in Government of Canada yields. Neither conversation is optional this quarter. Both are time sensitive in ways that will look different by October.