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: long-term rent, then your DTI

On a conventional, agency-backed loan, the rental-income path is built entirely on long-term market rent — so your nightly revenue doesn't come through it, and what does gets folded into your debt-to-income ratio rather than measured as coverage. For a lot of STR buyers, that single design fact decides the whole financing approach.

Here's the mechanics, per the current Fannie Mae Selling Guide (B3-3.8-01). When rental income is used to qualify and there's no lease to transfer, the qualifying 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. That figure is an estimate of long-term monthly market rent. The lender multiplies it by 75% (the other 25% is treated as absorbed by vacancy and maintenance), and the net result is added to — or, if it's a loss, subtracted from — the income side of your DTI. There is no step that converts nightly rates into monthly income; Fannie's own appraiser guidance says Form 1007 "was not designed" for short-term rentals.

On the canonical property, that means a lender doesn't see $63,000. It sees a four-bedroom house that might lease long-term 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. Your $63,000 underwrite never enters the calculation.

There is one important wrinkle, 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 agency limit that catches new buyers: if you have no prior rental-management history, the guidelines generally let the property's rent only offset its own payment, not add to your qualifying income — and with no housing payment of your own, you may not be able to use it at all (B3-3.8-01). 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. One representative program (Acra) states it qualifies on the lesser of in-place or market rent ÷ PITIA and will 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.

   YOUR UNDERWRITE:  ~$63,000/yr  (~$5,250/mo net)   ← the number YOU decide to buy on
        │
        ├── AGENCY (conventional) ────────────────────────────────────────────────
        │      rental-income path → long-term market rent ~$3,000/mo × 75% = $2,250
        │           → folded into your DTI (a liability here, not "coverage")
        │      business-income path → lender's choice; no 1007; business-income docs
        │      (nightly revenue itself: no mechanism on the rental path)
        │
        └── NON-AGENCY DSCR ──────────────────────────────────────────────────────
               the program sets the eligible method; it may use the more conservative
               supported figure among:
                 • 12-month actual history ....... strongest; needs a track record
                 • third-party projection (AirDNA) ... usually haircut by the lender
                 • long-term-rent fallback ~$3,000 ... can sink an STR-only deal
               → chosen "qualifying rent" ÷ PITIA $4,142 = the lender's DSCR

One property, several possible qualifying incomes. Which one a lender lands on — and whether the loan clears — turns on the method, not on the revenue you projected.

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?

Your action plan

1. Separate your two numbers. Keep your honest underwritten revenue for the buy decision; don't assume it's the lender's qualifying income.
2. Ask the method first. Before anything else, ask each lender exactly how they'll derive STR income — long-term 1007 rent, 12-month history, or a third-party projection — and how they'll document it.
3. Lead with actuals when you have them. A trailing 12-month history (payouts, PMS reports, deposits) is the strongest evidence and the least likely to be discounted.
4. Pin down the haircut. If a lender uses AirDNA or similar, ask what discount they apply and whether they'd fall back to long-term rent without it.
5. On agency, ask about business-income treatment. It's the lender's classification choice; if it's available, prepare the business-income documentation it requires.
6. Underwrite the fallback. Check whether the deal still qualifies if the lender reverts to long-term market rent. If it doesn't, you're relying on a method the lender may not use.

The bottom line

The revenue you project and the income a lender qualifies on are two different numbers, and financing gets decided on theirs. The agency path can't count your nightly revenue on the rental side at all — it uses 75% of long-term market rent and works it into your DTI — while a DSCR lender can use short-term income but derives it in one of three ways, often the most conservative. None of them simply adopt your pro-forma. So keep your underwrite for the decision it's built for, and treat the financing as a separate question with its own arithmetic: ask how the lender derives the income, bring the evidence that keeps them off the conservative fallback, and never assume your number is theirs.

About the author

Matt Nunn is the founder of Builders Finance. He has spent two decades working with the financial side of real estate businesses, and started Builders Finance to give short-term-rental operators the financial systems, frameworks, and plain-language education that most hosting advice skips over. Builders Finance publishes educational content for STR owners and is not a substitute for advice from your own qualified financial or tax professional.

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Educational information only — not individualized tax, legal, or investment advice. The worked example is an illustrative model, not a projection or a recommendation.