Family Loans Across the Border: Canada's Prescribed Rate, America's AFR, and the Paperwork That Keeps a Loan From Being a Gift

The intra-family loan is the tool families reach for when a gift feels too final and a bank feels too formal, and each country polices it with its own minimum-interest machinery. Canada's: interest-free or low-interest loans between family members don't create general imputed income, but two regimes give the rate teeth — attribution (income earned on funds lent to a spouse or minor-child structures attributes back to the lender unless the loan bears at least the prescribed rate, set quarterly, with interest actually paid by January 30 each year — the prescribed-rate loan being a deliberate income-splitting strategy in low-rate quarters, and a dead loan the first January the interest goes unpaid) and the ordinary requirement that a lender charging interest reports it as income. Loans to adult children carry no attribution — a Canadian parent may lend an adult child interest-free with no Canadian income consequence at all, which is why the parent-to-adult-child loan is Canada's cleanest family credit. The US's: the below-market loan rules impute interest on loans under the applicable federal rates — for a gift loan, the foregone interest is treated as a gift from lender to borrower (consuming annual exclusion or exemption) and as interest income to the lender, with a $10,000 de minimis exception and a $100,000 ceiling under which imputed interest is capped at the borrower's net investment income (zero if under $1,000) — the escape hatches that make modest US family loans practical. The cross-border pairings apply whichever rules reach each party: a Canadian parent lending a US-resident child triggers no Canadian attribution (adult child) and, as a foreign lender, structures around the US rules mostly through the child's side of the ledger (the below-market gift-loan analysis and the child's deduction position if the loan funds a home, where properly secured and documented interest may be deductible mortgage interest to the child — one reason the registered, secured, AFR-bearing version of the family mortgage is the standard cross-border structure); a US parent lending a Canadian child prices against the AFR to avoid deemed-gift accrual on the foregone interest; spousal loans across the border pair the prescribed-rate discipline with the marital gift rules from the mixed-marriage playbook; and in every configuration the interest actually paid is taxable income to the lender in the lender's country (with non-resident withholding rules mostly a non-issue for arm's-length-rate family interest, since the treaty and domestic exemptions have removed general withholding on most cross-border interest). What every configuration shares is the file: a written note (amount, rate, term, repayment schedule), security where the loan funds property, interest actually paid and traceably banked, and lender-side reporting of the interest — because both systems' fallback characterization for the undocumented family "loan" is a gift, discovered at the worst time: the audit, the divorce, the estate, or the sibling dispute where the ledger would have settled everything.

Key takeaways

• Canada: no attribution on loans to adult children (interest-free is clean); spousal and minor-structure loans need the prescribed rate with January-30 interest discipline; charged interest is the lender's income. The prescribed rate locks for the loan's life at the rate when made — low-rate quarters are loan-origination season.
• US: below-market loans impute interest at the AFR — gift-loan foregone interest is both a deemed gift and deemed interest income — softened by the $10,000 de minimis and the $100,000/net-investment-income cap. Loans at or above the AFR, documented, escape the regime entirely.
• The clean pairings: Canadian parent → US adult child (no attribution; structure to the US rules — at scale, an AFR-rate secured note; under the thresholds, simpler); US parent → Canadian child (AFR-rate note avoids the deemed-gift accrual); cross-border spousal loans (prescribed-rate discipline plus the marital gift caps).
• Interest flows are taxable where the lender lives: the Canadian lender reports US-child interest on the T1; the US lender reports on the 1040; treaty and domestic exemptions have largely eliminated withholding on ordinary cross-border interest — confirm per structure, then paper the payments.
• The home-loan variant earns its formality: registered security and market-structure terms can make the child's interest deductible (US mortgage-interest rules for the US child; and the loan survives lender death, borrower divorce, and bank refinancing questions) — the family mortgage is documented like a mortgage or it is a gift with extra steps.
• Forgiveness is a gift when it happens, planned or not: forgiving principal is a gift at that time (US annual exclusions and 709 tracking for US lenders; no Canadian gift tax but the estate's ledger cares) — the forgive-annually-by-exclusion program is legitimate and papered, while the note quietly ignored is the audit's favorite exhibit.

The loan file, standardized

One template serves every configuration: promissory note (parties, principal, rate with its source — prescribed or AFR — term, payment schedule, security if any); the funds' wire record; a payment ledger with the banking trail; the lender's annual interest reporting; security registration where real property is involved; and a family-file copy of the whole stack. Annual maintenance is two entries: interest paid by its deadline (January 30 for prescribed-rate loans; per the note otherwise) and the ledger updated. The file costs an hour at origination and converts the loan from a characterization argument into arithmetic — for the CRA, the IRS, the estate's executor, and the borrower's future ex-spouse alike.

Worked example

Three loans in one extended family. Loan one: a Waterloo father lends his Austin daughter US$300,000 toward a house — adult child, so no Canadian attribution regardless of rate; they structure it as a registered second mortgage at the AFR, interest-only with a five-year balloon: her properly-secured interest enters her US mortgage-interest position, his T1 reports the interest income, and her refinance two years later pays the note off against a ledger her bank accepted without a raised eyebrow. Loan two: the father lends his own spouse C$400,000 for her investment portfolio — the prescribed-rate loan, papered at origination in a low-rate quarter, interest paid every January 28 by transfer: the portfolio's income taxes to her at her lower rate, attribution held at bay by the discipline, and the one year the payment nearly slipped, the calendar reminder earned its keep — a missed January 30 would have attributed the portfolio's income back to him from that year forward. Loan three: the Austin daughter's American mother-in-law lends the couple US$60,000 for renovations, interest-free — under the US$100,000 ceiling with the couple's net investment income minimal, imputed interest rounds to zero and the de-minimis-adjacent structure needs only the note and ledger; she forgives US$38,000 of it over two years inside her and her husband's annual exclusions, papered as gifts when made. Three loans, three regimes, one template — and the family's estate file, decades early, already reads like a ledger instead of a negotiation.

Official sources

The CRA publishes prescribed interest rates quarterly, including the rate that applies to taxable benefits and to loans between related persons; a loan at the prescribed rate in effect when the loan is made, with interest paid by January 30 each year, avoids the attribution of income on funds loaned between spouses or to family trusts. — Canada Revenue Agency, Prescribed interest rates, https://www.canada.ca/en/revenue-agency/services/tax/prescribed-interest-rates.html

"The rules for below-market loans do not apply to any day on which the total outstanding amount of loans between the borrower and lender is $10,000 or less." For gift loans of $100,000 or less between individuals, the imputed interest "is limited to the amount of the borrower's net investment income for the year." — Internal Revenue Service, Publication 550, Investment Income and Expenses, https://www.irs.gov/publications/p550

Practitioner note

Family loans are gifts with better paperwork or gifts with worse outcomes, and the border doubles the referees: Canada's attribution machinery watches the spousal and minor-money, the AFR watches everything American, and both defer entirely to a boring file — note, rate, payments, ledger. Our origination template runs one hour and two rules: pick the rate regime the parties actually face, and calendar the interest like a covenant, because the prescribed-rate loan dies every January 31 somebody forgot.

See also: Browse every cross-border tax topic guide, organized by situation.

Next step

Fairlight prepares the family lending program — configuration-specific structuring against the prescribed rate and AFR, secured family-mortgage documentation, interest and forgiveness calendars, and the loan file both tax systems and the estate can read. See cross-border pricing or book a call.