NEWSROOM · CROSS-BORDER TAX
The Car Loan Interest Deduction Final Rule Draws a Line at the Border
Educational information only — not tax, legal or investment advice. Cross-border filing positions turn on individual facts; confirm yours with a qualified cross-border tax professional before acting.
Treasury and the IRS released the car loan interest deduction final rule on September 8, 2026, closing a rulemaking that opened with proposed regulations in January. TD 10054, published at 91 FR 57214 and effective November 9, 2026, puts detail behind one of the One Big Beautiful Bill’s most talked-about personal deductions: up to US$10,000 a year of interest on a loan used to buy a new car, claimable whether or not you itemise.
For anyone whose financial life crosses the 49th parallel, the headline number is not the interesting part. The interesting part is where the rule closes the door — and the one place it stays open wider than expected.
What does the car loan interest deduction final rule allow?
The deduction is narrow by design. Interest qualifies only if the loan was incurred after December 31, 2024, is secured by a first lien on the vehicle, and was taken to buy an applicable passenger vehicle for personal use. The regulations fix the personal-use test at the moment the debt is incurred — you qualify if you then expect personal use more than half the time — and say expressly that this is not an ongoing requirement.
The vehicle must clear a checklist: a car, minivan, van, SUV, pickup or motorcycle built for public roads, a motor vehicle under Title II of the Clean Air Act, gross vehicle weight rating under 14,000 pounds — and original use commencing with the first person to take delivery after it is sold, registered or titled, which is why used cars and lease buyouts fall outside the rule. Refinancing survives only up to the balance refinanced.
One limit is easy to misread. The US$10,000 ceiling is per federal tax return, not per vehicle — it applies per return regardless of filing status, and Treasury confirmed that a taxpayer with more than one qualifying loan aggregates the interest before the cap bites. A couple financing two cars does not get two caps.
Why does final assembly in the United States matter so much?
Because it is the first gate, and it is absolute. The regulations state that an applicable passenger vehicle cannot include any vehicle whose final assembly did not occur within the United States. No treaty override, no CUSMA accommodation, and no relief for the same model assembled in Ontario or Mexico.
Final assembly can be established from the vehicle identification number or from the final-assembly point on the vehicle label. The NHTSA VIN decoder reports build plant and country — a checkable fact before you sign, and an unfixable one afterwards.
Can a US citizen living in Canada claim it?
Possibly. The statute and final regulations do not appear to require that the taxpayer reside in the United States, or that the vehicle be registered or used there — the geographic test they impose is on where the car was built. A US citizen in Canada still files a Form 1040 on worldwide income, so such a taxpayer may potentially qualify if the vehicle and the loan otherwise satisfy every requirement, US final assembly included.
Treasury clearly had foreign lenders in mind. The reporting rules address foreign persons directly: a foreign recipient reports interest received at a US location, and interest received outside the United States only in narrow circumstances — broadly, a controlled foreign corporation, or one whose income is mostly effectively connected with a US trade or business. An ordinary Canadian bank will therefore issue no Form 1098-VLI. That makes substantiation harder without disqualifying the claim, because the obligation sits on the lender rather than standing as a condition of your deduction.
Two things do bite, and they bite hard.
The VIN is a statutory condition, not paperwork. Section 163(h)(4) provides that interest is not qualified passenger vehicle loan interest unless the taxpayer includes the vehicle identification number on the return for the year. Miss it and the deduction is gone.
The foreign earned income exclusion does not shelter you from the phase-out. The deduction phases out by US$200 for every US$1,000 (or part of one) of modified adjusted gross income above US$100,000, or US$200,000 on a joint return. And section 163(h)(4)(C)(ii)(II) defines modified adjusted gross income here as adjusted gross income increased by any amount excluded under sections 911, 931 or 933. A taxpayer earning US$150,000 who excludes US$100,000 does not get to test the phase-out against the US$50,000 that remains — the excluded Canadian salary is added straight back.
That mechanic will be familiar to anyone who has worked through how cross-border withholding under the One Big Beautiful Bill treats income that is off the return but not out of the calculation.
Does Canada give anything back on the other side?
No, and the asymmetry is the point. The CRA allows an interest deduction on money borrowed to buy a motor vehicle only where the vehicle earns business, professional, farming or fishing income. Interest on a purely personal car loan is not deductible in Canada at all. Where a vehicle does earn income, the deduction is capped: for new automobile loans entered into on or after January 1, 2026, Finance Canada holds the limit at C$350 per month, unchanged from the prior year.
So a dual citizen in Toronto with a US-assembled SUV financed through a Canadian bank may have a US deduction and no Canadian one. No Canadian tax is reduced, so there is no foreign tax credit interaction — the benefit lands entirely on the US side.
What about Canadians who are not US persons?
Largely outside it. The preamble states that a nonresident alien individual will generally not be allowed to deduct qualified passenger vehicle loan interest, because it attaches to a vehicle bought for personal use rather than to US effectively connected income. A snowbird who keeps a car in Arizona and files a Form 8840 is not the intended beneficiary. The group it genuinely reaches is Canadians who become US tax residents — someone moving south on a TN visa or a green card who buys a new US-assembled vehicle with a first-lien loan. It belongs on the Canadian departure checklist.
What this means for cross-border clients
- Check the build country before you sign. One VIN lookup settles whether the loan can ever produce a deduction.
- Put the VIN on the return. A statutory condition, not a supporting schedule.
- Do not assume the exclusion helps. Add back foreign earned income before estimating the phase-out.
- One cap per return. Two financed cars in one household share a single US$10,000 ceiling.
- Expect no Form 1098-VLI from a Canadian lender — keep records sufficient to substantiate the claim instead.
- Watch the clock. A four-year window, tax years 2025 through 2028, not a permanent feature.
The financing decision now carries a tax consequence that depends on where the car was built and which return you file. It sits alongside the larger questions in cross-border tax planning; our side-by-side of 2026 tax changes in the US and Canada and the current 2026 IRS figures supply the surrounding numbers.
Frequently asked questions
Does the deduction apply to a vehicle I keep in Canada?
The statute and final regulations do not appear to impose a requirement that the vehicle be registered or used in the United States. The geographic test is final assembly, which must have occurred in the United States. Registration and titling matter in a different way — they help fix when original use of the vehicle began.
I claim the foreign earned income exclusion. Does that reduce my income for the phase-out?
No. Section 163(h)(4)(C)(ii)(II) defines modified adjusted gross income for this deduction as adjusted gross income increased by amounts excluded under sections 911, 931 and 933, so excluded foreign earned income is added back before the phase-out is applied.
What records should I keep if my lender never files a Form 1098-VLI?
Treasury declined to prescribe a substitute checklist and pointed instead to the general substantiation rule under section 6001 and Treas. Reg. section 1.6001-1(a): keep records sufficient to establish the deduction. In practice that could include the loan agreement, documentation showing the lender’s first lien, the VIN and purchase records, evidence of US final assembly, and records of the interest actually paid.
If my spouse and I each finance a car, do we get US$10,000 each?
No. The limit applies per federal tax return regardless of filing status. Interest from multiple qualifying loans is aggregated first, then the single cap applies.
How long does this last?
It applies to taxable years beginning after December 31, 2024 and before January 1, 2029, for loans incurred after December 31, 2024. The final regulations take effect November 9, 2026.
Talk it through
Vehicle financing is rarely the biggest decision on a cross-border household’s list, but it is a clean illustration of how a US rule and a Canadian rule can point in opposite directions on the same transaction. If you are planning a move, buying on one side and living on the other, or want a second read on a filing position, you can book an introductory conversation. Lucas’s book, Crossing the 49th Parallel, covers the wider retirement and tax picture.
Sources
- Car Loan Interest Deduction, final regulations (TD 10054), 91 FR 57214 — IRS, published September 8, 2026, effective November 9, 2026. RIN 1545-BR75. Official PDF.
- Car Loan Interest Deduction, notice of proposed rulemaking — IRS, published January 2, 2026.
- 26 U.S.C. § 163 — Office of the Law Revision Counsel. Section 163(h)(4) carries the US$10,000 limitation, the phase-out, the modified adjusted gross income definition at (C)(ii)(II), and the VIN condition.
- VIN Decoder — National Highway Traffic Safety Administration.
- Motor vehicle – Interest — Canada Revenue Agency.
- Government announces the 2026 automobile deduction limits and expense benefit rates for businesses — Department of Finance Canada, January 14, 2026.
- Tax inflation adjustments for tax year 2026, including amendments from the One, Big, Beautiful Bill — IRS.
