How Lenders Calculate Short-Term Rental Income

The number you project is not the number they qualify

Every STR owner underwrites a revenue figure. Every lender derives its own. Those two numbers are rarely the same, and the loan is decided on the lender's — not yours. Understanding how each lender builds that figure is the difference between a smooth close and a pre-approval that evaporates at underwriting.

On the canonical deal, you've done the honest work: about $63,000 of net annual revenue, roughly $5,250 a month. That's the revenue figure you carry into your own deal analysis — an input to the buy decision, not the decision itself. But when you go to finance, the lender doesn't inherit your spreadsheet. It runs the property through its own income-derivation method — and depending on the loan type, that method might land at your $5,250, at a long-term-rent figure less than half of it, or at a number that can't be used to qualify at all. This guide walks the two worlds where that happens: the agency (conventional) path, and the non-agency DSCR path.

The agency path: a narrow door for STR income

On a conventional, agency-backed loan, short-term-rental income gets through only a narrow door — and whatever gets through can offset the property's own payment, never add to your income. For a lot of STR buyers, that single design fact still decides the whole financing approach.

Here's the mechanics, as of September 2026. Fannie Mae's Selling Guide now has a short-term-rental rule of its own (B3-3.8-03, added September 2, 2026, and required for applications dated on or after November 1, 2026). It applies only to a one-unit investment property that is legally permitted to operate as a short-term rental (and not to income from an accessory unit). How the income is established depends on the transaction. On a purchase, the gross monthly figure comes either from the appraiser's rent schedule (Form 1007, completed on long-term rentals) or from validated data for comparable short-term rentals — MLS or property-management records, averaging the comparables' rates and multiplying by the average days rented — and the lender takes 50% of it as net rental income (the other half is treated as vacancy and maintenance). On a refinance of a property already on your tax return, the lender instead runs a cash-flow analysis of your Schedule E, averaged over 12 months. Either way, the result is set against the property's full PITIA: a positive figure can only offset that payment, and a negative one is added to your debt-to-income ratio. You also need a current housing payment of your own to use any of it.

The ordinary long-term rule still exists alongside it (B3-3.8-02): when rental income is used to qualify and there's no lease to transfer, the figure comes from the appraiser's Form 1007 (single unit) or Form 1025 (2–4 units) — Freddie's equivalents are Form 1000 and Form 72 — as an estimate of long-term monthly market rent, and the lender takes 75% of it. Fannie's own appraiser guidance says Form 1007 "was not designed" for short-term rentals, which is why the separate short-term rule exists.

On the canonical property, neither route sees $63,000. On the long-term route, a lender sees a four-bedroom house that might lease for ~$3,000 a month, takes 75% ($2,250), and since that's short of the ~$4,142 payment, adds the shortfall to your DTI as a liability. On the short-term route, even if comparable short-term rentals supported your full ~$5,250 a month, 50% of it is ~$2,625 — still short of the payment, so a shortfall still lands in your DTI. Your $63,000 underwrite never enters the calculation as income.

There is one other route, and it's a lender's choice rather than yours: Fannie's June 2024 Appraiser Update says a lender may elect to treat STR income as business income instead of rental income — in which case the Selling Guide's business-income rules apply and no Form 1007 is needed. That's a real alternative pathway, but it depends entirely on how a given lender decides to classify the income, and it comes with the documentation burden of business income (tax returns, a track record). You can't assume it; you have to ask for it.

And one more limit catches new buyers on the long-term route: with less than 12 months of rental-management experience, the property's rent can only offset its own payment, not add to your qualifying income (B3-3.8-02) — and on either route you need a current housing payment of your own to use the property's rental income at all. So on the agency path, a first-time STR buyer often can't lean on rental income no matter how strong the projection.

The DSCR path: a few common ways to the same box

Non-agency DSCR lenders can qualify on short-term income — but "qualifying STR income" isn't one defined number. Lenders derive it in several ways, and many take the most conservative supported figure. This is the crux of the whole guide: getting a DSCR loan approved on your STR revenue depends less on your projection than on which method the lender uses to test it.

Three common methods you'll encounter:

A 12-month operating history. If the property already runs as an STR, the lender can use its documented trailing income — platform payout statements, property-management reports, or bank deposits. A documented operating history can give a lender stronger income evidence than a projection alone, which is why a seasoned STR is often easier to finance than a fresh one.

A third-party projection. For a property without a track record, some lenders accept a market-data estimate from a service like AirDNA or Rabbu — but they commonly apply a haircut (a discount that varies by lender) before it counts, precisely because a projection isn't a receipt.

A fallback to long-term market rent. When there's no history and the lender won't lean on a projection, it can revert to the appraiser's long-term rent — the same figure the agency path would use. On a property that only pencils as a nightly rental, that fallback can quietly sink the DSCR.

Because the method is lender-specific, the same property produces different qualifying income at different DSCR shops. Some programs qualify on the lesser of in-place or market rent ÷ PITIA and accept 12-month STR ledgers; others weight AirDNA differently or require more history. None of them simply adopt your underwritten pro-forma. Present your evidence, but confirm the method.

What to bring, by method

Because the method drives the number, the way to protect a deal is to walk in with the evidence each method needs — and to ask which one the lender will apply. The stronger your documentation, the less a lender has to fall back to the conservative option.

If the property has a history, gather the trailing 12 months of platform payout statements, any property-management income reports, and the bank deposits that corroborate them — actual receipts beat any projection. If it's a fresh purchase, have a clean third-party market report ready, and ask the lender directly whether they'll use it, how they'll haircut it, and whether they'd otherwise revert to long-term rent. On the agency side, if a lender is open to treating the income as business income, be ready for the business-income documentation (returns, a track record) that path requires. In every case, the question to ask out loud, before you're under contract, is simply: how will you derive and document the income on this property?