Your Lease Has an Interest Rate. Federal Rules Bar the Dealer From Calling It an APR.

If you’re thinking about leasing your next car because the loan payments look ugly, you’re about to pay interest at a rate the paperwork isn’t allowed to call an APR.

That’s not a dealer trick. It’s federal law.

The rule that hides the rate

Regulation M, the federal rule for consumer leases, spells out what your lease contract has to show. The capitalized cost (the price you’re leasing from), the residual value (what the car is assumed to be worth at the end), the depreciation, and the rent charge, in dollars. Then it adds a twist. If the leasing company quotes a percentage rate at all, it must attach a warning that “this percentage may not measure the overall cost of financing this lease.” And it “shall not use the term ‘annual percentage rate.’”

So the number that drives your finance cost travels under a different name: the money factor. It looks like 0.00250. It means nothing to a normal person. And the Federal Reserve’s own leasing guide says the money factor “typically is not disclosed to you.”

Translation: the one figure you’d use to compare a lease to a loan is the one you’re least likely to see.

Why this is coming up now

Leasing is creeping back. Leases made up roughly 30% of new-vehicle deals before the pandemic, fell to 17% during the shortage, and recovered to about 23% in the first half of 2026, Fortune reported this week, citing J.D. Power. The same story put the average financed new-car payment at a record $787 a month. When the loan payment hurts, the lease quote starts looking friendly.

The math they skip

The Fed gives the formula. Your monthly rent charge is the money factor times the sum of the adjusted cap cost and the residual. Since that sum is about twice the average balance you’re paying on, multiplying the money factor by 2,400 turns it into an approximate annual rate. Southeast Toyota Finance publishes the same rent-charge formula, and a CFP writing in Medical Economics calls 2,400 “an industry financing constant.”

Run it on a typical deal: a $45,000 adjusted cap cost and a $27,000 residual on a 36-month lease.

At a money factor of 0.00250 (about 6.0%), the rent charge is $180 a month.

At 0.00350 (about 8.4%), it’s $252 a month.

That’s $72 a month, or $2,592 over three years, for a difference you’d never spot on the payment line. A thousandth of a point looks like a rounding error. It’s a vacation.

What to do before you sign

Ask for the money factor in writing, next to the cap cost and the residual. Multiply it by 2,400. Then compare that number to the rate your bank or credit union quotes you on a loan for the same car. Run the loan side through our loan calculator so you’re comparing payments on the same price.

If the lease rate comes in well above your loan quote, push back. That same Medical Economics piece warns that dealers “simply jack up the money factor” so they can cut the sale price to the bone, which makes the deal look great on the one number you’re watching. If they won’t say what the money factor is, take the rent charge on the contract, divide it by the number of payments, then divide again by the adjusted cap cost plus the residual. A phone calculator does it in a minute.

Your call whether a lease fits how you drive. Just don’t sign one without its rate. Our auto loan guide and the best loans list are there for the other side of the comparison.

How Candid Yak makes money. Some of the products we write about pay us if you apply or sign up through our links. That never changes our verdict, our rankings, or the numbers in this article. We call a bad deal a bad deal whether it pays us or not. Some brands shown in our comparison tools are placeholder examples while we finalize partner agreements, and we label them as such.