What Is Boot in a 1031 Exchange?
Boot is any value you receive in a 1031 exchange that is not like-kind real property — most commonly leftover cash from the sale, or a reduction in mortgage debt when the replacement property carries less debt than the property you sold. Boot doesn’t disqualify the exchange, but it is taxable: under IRC §1031(b), your gain is recognized up to the amount of money and non-like-kind property received. To defer 100% of your tax, you generally need to receive zero boot.
Where the term comes from
“Boot” isn’t in the tax code — it’s exchange jargon for something given or received “to boot” (in addition) to even out a trade. Section 1031 itself just calls it “other property or money.” The statute’s rule is simple: if an exchange would otherwise qualify for full nonrecognition but you also receive money or other non-qualifying property, “the gain, if any, to the recipient shall be recognized, but in an amount not in excess of the sum of such money and the fair market value of such other property” (IRC §1031(b)).
Two things follow from that sentence:
- Boot makes the exchange partially taxable, not invalid. The rest of the gain stays deferred.
- Recognized gain is capped at your realized gain. If you receive $50,000 of boot but your total gain on the sale was only $30,000, you recognize $30,000 — never more than the actual gain.
One asymmetry worth knowing: while boot triggers gain, it does not let you deduct a loss. IRC §1031(c) provides that no loss is recognized in a partially non-like-kind exchange.
The two main kinds of boot
| Type | What it is | Common cause |
|---|---|---|
| Cash boot | Money (or non-like-kind property) you actually receive | Buying a cheaper replacement property; taking cash out at closing; leftover exchange funds returned by the qualified intermediary at the end of the exchange |
| Mortgage boot (debt-relief boot) | Net reduction in your debt load | The mortgage paid off on the sold property exceeds the debt on the replacement property, and you didn’t make up the difference with cash |
Cash boot
Any exchange proceeds that don’t end up in like-kind replacement real estate come back to you as taxable cash boot. This includes funds your qualified intermediary returns after the exchange closes. (Which properties count as like-kind in the first place is covered in what qualifies for a 1031 exchange.)
Mortgage boot
Treasury regulations treat debt relief as if you’d received cash: “the amount of any liabilities of the taxpayer assumed by the other party to the exchange (or of any liabilities to which the property exchanged by the taxpayer is subject) is to be treated as money received by the taxpayer upon the exchange” (Treas. Reg. §1.1031(d)-2). Pay off a $200,000 mortgage at sale and take on only $150,000 of debt on the new property, and — absent an offset — you have $50,000 of mortgage boot even though you never touched the money.
The netting rules: what offsets what
The examples in Treas. Reg. §1.1031(d)-2 establish an asymmetric set of offsets:
- Debt relief CAN be offset by new debt. Liabilities you take on with the replacement property net against liabilities you were relieved of. Only the net reduction is boot.
- Debt relief CAN be offset by cash you add. Bringing fresh cash to the replacement closing reduces mortgage boot dollar for dollar.
- Cash received CANNOT be offset by new debt. The regulation is explicit that “consideration received in the form of cash or other property is not offset by consideration given in the form of an assumption of liabilities.” You can’t pocket exchange cash and cure it by borrowing more on the new property.
The Form 8824 instructions apply the same logic: only the excess of liabilities the buyer assumed over the liabilities you assumed, cash you paid, and non-like-kind property you gave up counts as amount received — and the total can be reduced (not below zero) by your exchange expenses, such as qualified intermediary fees and certain closing costs.
How boot is taxed
Boot is taxed as recognized gain in the year of the exchange, reported on IRS Form 8824 — the form caps recognized gain at the smaller of the boot received or your total realized gain. The character of that gain matters:
- Depreciation-related gain comes out first, at less favorable rates. Form 8824 has a dedicated line (line 21, “ordinary income under recapture rules”) for gain recharacterized as ordinary income under sections 1245 and 1250. For real estate depreciated straight-line, the depreciation-attributable portion of recognized gain is generally unrecaptured section 1250 gain, taxed at a maximum 25% rate rather than the 0/15/20% long-term capital gains rates (IRS Topic 409).
- The remainder is capital gain, long-term if you held the relinquished property more than a year, and it may also be subject to the 3.8% net investment income tax and state income tax depending on your situation and state.
In practice this means a “small” amount of boot can be taxed at a higher blended rate than investors expect, because the recapture-flavored gain is recognized before the lower-rate capital gain.
Worked example (hypothetical illustration)
The numbers below are round, hypothetical figures for illustration only — not a real transaction — and they ignore closing costs and exchange expenses to keep the arithmetic clean.
An investor sells a rental property and trades down into a cheaper one:
| Item | Amount |
|---|---|
| Sale price of relinquished property | $500,000 |
| Adjusted basis | $250,000 |
| Realized gain (500,000 − 250,000) | $250,000 |
| Mortgage paid off at sale | $200,000 |
| Net proceeds held by the qualified intermediary | $300,000 |
| Purchase price of replacement property | $450,000 |
| New mortgage on replacement property | $200,000 |
| Exchange cash used at purchase (450,000 − 200,000) | $250,000 |
Boot calculation:
- Cash boot: $300,000 of exchange proceeds − $250,000 reinvested = $50,000 returned to the investor.
- Mortgage boot: $200,000 of debt relief − $200,000 of new debt = $0 (fully replaced).
- Total boot: $50,000 — exactly the amount by which the investor traded down ($500,000 → $450,000).
Result: the investor recognizes gain of $50,000 (the boot, which is less than the $250,000 realized gain) and defers the remaining $200,000. If, say, the investor had claimed substantial straight-line depreciation on the old property, that $50,000 would generally be taxed first as unrecaptured section 1250 gain at up to 25% before any of it qualifies for the lower capital-gains rates. Run your own numbers with a 1031 exchange calculator.
Partial exchanges are allowed
Receiving boot is sometimes deliberate. An investor who wants to pull some cash out of a property — to pay down other debt, cover expenses, or simply diversify — can do a partial 1031 exchange: defer most of the gain and consciously accept tax on the boot. The exchange remains valid; only the boot portion is recognized. The key is to make that decision before closing, with your tax advisor, because the netting rules above determine exactly how much tax the cash-out triggers.
How to avoid boot
To defer the entire gain, structure the exchange so nothing comes back to you:
- Buy equal or greater value. The replacement property (or properties) should cost at least as much as the relinquished property sold for.
- Reinvest all net proceeds. Every dollar the qualified intermediary holds should go into the replacement purchase. Don’t have leftover funds returned.
- Replace the debt — or offset it with cash. Match or exceed the mortgage paid off at sale with new financing, or cover the shortfall with additional cash from outside the exchange (Treas. Reg. §1.1031(d)-2).
- Never touch the money mid-exchange. Actual or constructive receipt of proceeds disqualifies the exchange entirely under the qualified-intermediary safe harbor in Treas. Reg. §1.1031(k)-1 — that’s worse than boot. Choosing a reputable QI matters; see our guide to 1031 exchange companies.
If you’re struggling to find a replacement property large enough to absorb all your value and equity within the 45-day window, two common paths are a reverse 1031 exchange (acquire first, sell second) or fractional interests such as a Delaware statutory trust, which can be sized to soak up a precise dollar amount of remaining exchange funds.
Frequently asked questions
No. Boot makes the exchange partially taxable, not invalid. Under IRC §1031(b), gain is recognized up to the amount of money and non-like-kind property you receive, and the rest of your gain remains deferred. What does disqualify the exchange is taking actual or constructive receipt of the sale proceeds outside the qualified-intermediary safe harbor.
Mortgage boot (debt-relief boot) is a net reduction in your debt: the mortgage paid off on the property you sold exceeds the debt on the replacement property. Treasury Regulation §1.1031(d)-2 treats that debt relief as money received. You can offset it by taking on equal or greater debt on the replacement property or by adding cash of your own.
Boot is recognized gain in the year of the exchange, capped at your total realized gain, and reported on IRS Form 8824. Part of it may be ordinary income under the section 1245/1250 recapture rules, and depreciation-attributable gain on real estate is generally unrecaptured section 1250 gain taxed at a maximum 25% rate; the remainder is capital gain.
No. Under Treasury Regulation §1.1031(d)-2, cash or other property you receive is not offset by liabilities you assume. New debt can offset old debt (avoiding mortgage boot), and cash you pay in can offset debt relief — but cash you take out is taxable boot regardless of how much you borrow on the replacement property.
Yes. You can deliberately take some cash out of the exchange and pay tax only on that boot while deferring the rest of the gain. The exchange remains valid. Because of the netting and recapture rules, it's worth modeling the tax cost with an advisor before closing rather than after.
This article is for educational purposes only and is not legal or tax advice. Boot and gain recognition are governed by IRC §1031 and the Treasury Regulations; consult a qualified tax professional or attorney about your specific situation.
Primary sources: IRC §1031 (Cornell LII) · Treas. Reg. §1.1031(d)-2 (Cornell LII) · Treas. Reg. §1.1031(k)-1 (Cornell LII) · IRS Form 8824 & Instructions · IRS Topic 409, Capital Gains and Losses
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