45-Day Rule (Identification Period)
The 45-day rule requires a 1031 exchanger to identify replacement property in writing, delivered to the Qualified Intermediary, within 45 calendar days of closing on the relinquished property.
What it means
The 45-day identification deadline is the first of two hard deadlines in every 1031 exchange. The clock starts the day after the relinquished property closes. Identification must be in writing, signed by the taxpayer, delivered to the QI (not to the seller or a related party), and specific enough that the property is unambiguously identifiable — street address, legal description, or APN.
The rule is unforgiving. Day 45 is a calendar day, including weekends and holidays. Missing it is fatal to the exchange: the sale becomes a taxable event.
An exchanger may identify up to three properties under the Three-Property Rule, or more under the 200% Rule or 95% Rule. Identifications may be revoked and replaced any time before midnight of day 45, but the list is frozen thereafter.
Example
Close the downleg on March 1. Day 1 is March 2. Day 45 is April 15. By that date, the identification form must be signed and delivered to the QI.
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