1031 Exchange Timeline: The 45-Day and 180-Day Rules Explained

1031 Exchange Timeline Overview

A 1031 exchange has two hard deadlines that begin running the day you close the sale of your relinquished property. These deadlines are statutory, meaning Congress set them in the tax code (IRC 1031(a)(3)), and they cannot be extended by anyone.

The Two Deadlines

The 1031 Exchange Timeline, Visualized

Property Identification Rules

The IRS provides three alternative rules for identifying replacement properties. You only need to satisfy one.

1. Three-Property Rule (Most Common)

Identify up to three replacement properties of any value. You do not need to acquire all three; you just need to close on at least one. This is the simplest and most commonly used rule.

Example: You sell a $500K property. You can identify a $300K condo, a $600K duplex, and a $1.2M apartment building. As long as you close on one (or more), the exchange works.

2. Two Hundred Percent Rule

Identify any number of properties, as long as their combined fair market value does not exceed 200% of the relinquished property's sale price.

Example: You sell for $500K. You can identify properties totaling up to $1,000,000. That could be four properties at $250K each, or ten properties at $100K each.

3. Ninety-Five Percent Rule

Identify any number of properties of any value, but you must acquire at least 95% of the total value of all identified properties. This is rarely used because failing to close on even one identified property can disqualify the entire exchange.

Identification Requirements

• Written. Must be in writing, signed by you, and delivered to the QI.
• Unambiguous. Include the street address, legal description, or other clear identifier for each property.
• Timely. Must be received by the QI by midnight on the 45th day.
• Revocable. You can revoke and replace identifications before the deadline.

No Extensions, No Exceptions

Both deadlines are counted in calendar days. Weekends count. Federal holidays count. If day 45 lands on a Sunday, your identification is due that Sunday, not the following Monday. The regulations end the identification period at midnight on the 45th day, full stop. Missing it by an hour has the same result as missing it by a month: the exchange fails, and the entire gain, including depreciation recapture and capital gains tax, comes due for the year of the sale.

Disaster Relief Is the Only Out

The one exception is a federally declared disaster. Under Revenue Procedure 2018-58, taxpayers affected by a declared disaster can postpone both the 45-day and 180-day deadlines to the later of 120 extra days or the general postponement date in the IRS disaster notice, capped at one year and at the return due date including extensions. This relief is automatic in scope but narrow in reach: it requires a declared disaster that actually affects your exchange. Nothing else, not financing delays, not a seller walking, not a QI error, moves either deadline.

The Q4 Trap, Worked Out

Here is the return-due-date trap with real dates. Say you close the sale of a rental on November 20, 2026:

Without an extension, your exchange period ends on April 15, 2027, day 146. You lose 34 days of closing runway. File Form 4868 by April 15 and your return due date moves to October 15, 2027, which restores the full 180 days and puts your closing deadline back at May 19, 2027. Note that an extension to file is not an extension to pay; any tax you expect to owe for 2026 is still due April 15.

Reverse Exchange Timeline: Same Clock, Run Backward

In a reverse exchange you buy the replacement property first and sell your old property second. Because you cannot hold title to both, an exchange accommodation titleholder (EAT) takes title to one of the properties and parks it. Under the Revenue Procedure 2000-37 safe harbor, the same numbers apply in mirror image: you have 45 days from the day the EAT acquires the parked property to identify what you will sell, and the parking arrangement must wrap up within 180 days. Miss the 180-day parking limit and you fall outside the safe harbor. The mechanics, costs, and financing wrinkles are covered in our reverse 1031 exchange guide.

Common 1031 Timeline Mistakes

1. Not Filing a Tax Extension

If you sell a property in Q4, your tax return due date (April 15) may arrive before the 180th day. Without a filed extension, the exchange period ends on your return due date. This is the single most common preventable failure.

2. Waiting Until Day 44 to Identify

Procrastination kills exchanges. If you wait until the last days, you may rush into a bad deal or miss the deadline entirely due to a simple email failure or miscommunication with the QI. Start looking for replacement properties before you close the sale.

3. Touching the Proceeds

Exchange funds must be held by the qualified intermediary. If sale proceeds hit your bank account, even briefly, the exchange is disqualified. Ensure your closing agent wires directly to the QI.

4. Identifying Non-Qualifying Property

The replacement property must be held for investment or business use. Identifying a property you intend to use as your primary residence does not qualify. Vacation homes are a gray area; the IRS requires at least two years of rental use (Revenue Procedure 2008-16).

5. Ignoring Boot

Boot is any non-like-kind property received in the exchange, including cash left over and debt reduction. If you sell a $500K property with a $300K mortgage and buy a $500K property with a $200K mortgage, you have $100K of mortgage boot that is taxable.

6. Failing to Account for Closing Costs

Not all closing costs reduce boot. Expenses like prorated rent, security deposits, and some loan fees do not count as exchange expenses. Work with your CPA to model the exact numbers before closing.