The 45-day rule: within 45 calendar days of selling, you must identify potential replacement properties in writing, following strict limits on how many you can name.
The 180-day rule: you must close on the replacement within 180 calendar days of the sale — or your tax return due date, whichever comes first.
A qualified intermediary must hold the funds between sale and purchase. If the money touches your hands, the exchange fails — this is called constructive receipt, and the rule has no exceptions worth testing.
“Like-kind” means real property for real property, held for investment or business use. Since 2018, personal property no longer qualifies.
Any cash you keep — or debt you shed without replacing — is taxable “boot.” To fully defer, reinvest everything and replace your debt level.
The exchange must be set up BEFORE you close the sale. You cannot decide to do a 1031 after the proceeds hit your account.
Reverse exchanges (buy the replacement first, sell later) exist, but they are more complex and more expensive — and the same clock still ticks.