Boot is anything you receive in a 1031 exchange that is not like-kind real property — and it is the part that gets taxed. This guide explains what creates boot, how cash boot and mortgage (debt-relief) boot are taxed, and how to structure your exchange so you defer the maximum gain.
General information only — not tax, legal, or financial advice. A 1031 exchange has strict, unforgiving deadlines and significant tax consequences. Work with a CPA and a qualified intermediary (QI) before you act. A REALTOR® cannot serve as your QI. Verify current IRS and California FTB rules with a licensed tax professional.
What boot means
Boot is shorthand for value you receive in an exchange that is not like-kind real property. Receiving boot does not necessarily disqualify the whole exchange — but it makes that portion taxable. The rest of the gain can still be deferred.
There are two main flavors: cash boot and mortgage (debt-relief) boot.
Cash boot
Cash boot is the simplest: any net cash or non-like-kind property you pocket from the transaction. If you sell for more than you reinvest and keep the difference, that difference is cash boot and is generally taxable up to your realized gain.
- Sale proceeds you do not reinvest.
- Cash taken out at closing.
- Non-real-property assets received in the deal.
Mortgage (debt-relief) boot
Mortgage boot arises when the debt on your replacement property is less than the debt that was paid off on your relinquished property. That reduction in liabilities is treated as if you received value — so it can be taxable even if you never touched any cash.
You can sometimes offset mortgage boot by adding cash to the replacement purchase, increasing replacement debt, or both. Net cash and net debt are evaluated together — model it with your CPA.
How to defer all gain
- Reinvest 100% of your net equity (sale proceeds after costs and debt payoff).
- Acquire replacement property of equal or greater value than what you sold.
- Take on debt on the replacement equal to or greater than the debt you paid off (or offset any shortfall with new cash).
- Let all funds flow through your qualified intermediary — do not take constructive receipt.
- Avoid pulling cash out at closing.
Worked example
You sell a property for $1,000,000 with a $400,000 mortgage, netting $600,000 of equity after costs. To fully defer, you buy replacement property worth at least $1,000,000, reinvest the full $600,000 equity, and take on at least $400,000 of new debt. If you only buy a $900,000 property, the $100,000 shortfall is boot — and taxable. If you take only $300,000 of new debt without adding cash, the $100,000 debt reduction is mortgage boot.
How Brian helps
Brian helps you target replacement property at the right price and debt level so you do not accidentally create boot, and he can structure backups (including a value-absorbing option) to soak up leftover equity within your identification limits.
Frequently Asked Questions
What is boot in a 1031 exchange?
Boot is any value you receive that is not like-kind real property — cash, debt relief, or other property. It is taxable up to the amount of your realized gain.
What is the difference between cash boot and mortgage boot?
Cash boot is net cash or non-like-kind property you receive. Mortgage boot is the reduction in debt when your replacement property has less debt than your relinquished property paid off.
Does receiving boot ruin my whole exchange?
No. Boot only makes that portion taxable; the remaining gain can still be deferred, assuming the exchange is otherwise valid.
How do I avoid mortgage boot?
Take on replacement debt at least equal to the debt you paid off, or add cash to the replacement purchase to offset the difference. Net debt and net cash are evaluated together.
How much do I need to reinvest to defer all gain?
Generally you must reinvest all net equity and buy replacement property of equal or greater value and equal or greater debt. Any shortfall becomes taxable boot.
Is this tax advice?
No. This is general educational information. Confirm your boot calculation and exchange structure with a CPA and qualified intermediary.
