Two loans on the same house, at the same desk, with very different down payments. Which one you qualify for isn’t a preference you state. It’s a question of fact about how the house will be used, and the lender writes the answer into the file.
What counts as a second home?
A place you keep for yourself. Fannie Mae’s occupancy rules set out what a second home has to be, and the list is short enough to read in full. It “must be occupied by the borrower for some portion of the year,” “is restricted to one-unit dwellings,” “must be suitable for year-round occupancy,” and “the borrower must have exclusive control over the property.” Then the two that matter here: it “must not be rental property or a timeshare arrangement,” and it “cannot be subject to any agreements that give a management firm control over the occupancy of the property” (B2-1.1-01, dated 10/05/2022).
An investment property gets one line in the same section: “An investment property is owned but not occupied by the borrower.”
A house you list year-round, with a co-host taking bookings, is the second definition, not the first. Describing it as a second home on the application is a false statement on a mortgage document, and the “exclusive control” and “management firm” clauses exist precisely to catch it. There is no version of this where you get the cheaper loan for a full-time rental.
How much less do you put down?
The published minimums are five points apart, and in practice the gap is wider. Freddie Mac’s maximum LTV table allows a loan of up to 90% of value on a one-unit second home, and up to 85% on a one-unit investment property. Lenders routinely ask for more than the minimum on a rental, and 25% down is common.
Take a $350,000 house furnished for $25,000, with closing costs at 3% of the price.
| Second home, 10% down | Investment, 25% down | |
|---|---|---|
| Down payment | $35,000 | $87,500 |
| Closing costs (3% of the price) | $10,500 | $10,500 |
| Furnishing | $25,000 | $25,000 |
| Cash invested | $70,500 | $123,000 |
These are example figures, not a quote.
That is $52,500 of difference, and almost all of it is the down payment. What furnishing actually costs covers the $25,000 line and the budgets either side of it.
What does the cheaper loan cost each month?
More, every month, for two reasons. The loan is bigger, and under 20% down it carries mortgage insurance.
Mortgage insurance protects the lender, not you, and a conventional lender asks for it when the down payment is under “20 percent of the purchase price” (CFPB). The short-term rental calculator estimates it at 0.84% of the loan a year where you haven’t typed your lender’s figure, and on the $315,000 loan below that is $221 a month. Its Mortgage insurance line says it ends in year 10, when the loan is down to 78% of the price.
The house below books at $375 a night at 65% occupancy, which is 237 nights and $88,969 a year. The second-home loan is 10% down at 6.75%; the investment loan is 25% down at 7.25%. Both rates are the example’s assumption.
| Second home, 10% down | Investment, 25% down | |
|---|---|---|
| Revenue | $7,414 | $7,414 |
| Mortgage | −$2,043 | −$1,791 |
| Mortgage insurance | −$221 | – |
| Platform fee (15.5% of revenue) | −$1,149 | −$1,149 |
| Management or co-host (20% of revenue) | −$1,483 | −$1,483 |
| Property taxes | −$350 | −$350 |
| Insurance | −$200 | −$200 |
| Utilities | −$350 | −$350 |
| Cleaning | −$300 | −$300 |
| Supplies | −$150 | −$150 |
| Maintenance (5% of revenue) | −$370 | −$370 |
| Big replacements (5% of revenue) | −$371 | −$371 |
| Cash flow each month | +$427 | +$900 |
The cheaper loan clears $473 a month less: $252 of it is the larger mortgage payment and $221 is the insurance. Over the 112 months the insurance runs, that line alone is about $24,700.
So the two loans trade the same money in opposite directions. The second-home loan keeps $52,500 in your pocket at closing and gives back $473 a month. The investment loan takes the $52,500 and hands you a house that clears more than twice as much from the first month.
Can the rent help you qualify either way?
Only on the investment loan. Fannie Mae’s short-term rental rule applies to “One-unit investment properties only,” and on a purchase the lender multiplies the monthly gross rent from a rent schedule or validated short-term rental data by 50% and subtracts the property’s full payment. A positive result can offset that payment and nothing else; a negative one goes into your debt-to-income ratio (B3-3.8-03, dated 09/02/2026).
A second home gets none of that. Because it isn’t rental property under the occupancy rules, there is no rental income to count, and you qualify on your own income carrying both housing payments. That is the part people miss when they chase the smaller down payment: the cheaper loan is also the harder one to qualify for, on any house whose numbers depend on the bookings. Using Airbnb income to qualify goes through the paperwork.
Which one fits what you’re actually doing?
Answer the use question first, then price the loan.
- You’ll use it yourself and leave it empty the rest of the year. That is a second home, and the 10% down payment is yours. Don’t build a cash flow projection on a house you also want free in August.
- You’ll rent it whenever it will book. That is an investment property. Budget 25% down, no mortgage insurance, and the 50% rule above if the bookings need to help you qualify.
- You’ll do a bit of both. Say so to the lender and let them classify it. Mixed use is common and the rules are written for it; what breaks is deciding for yourself after closing.
Then check the insurance separately, because a standard homeowners policy on a second home generally won’t cover paying guests: what a homeowners policy does and doesn’t cover for an Airbnb. Run both versions of the loan in the calculator before you talk to anyone, and the conversation gets much shorter. How to analyze an Airbnb has the rest of the inputs.