The 1031 Exchange Timeline: 45 and 180 Days

A Section 1031 exchange lets you defer capital gains tax when you sell investment or business real estate and reinvest the proceeds into "like-kind" replacement property. The tax deferral is powerful, but it is not automatic. It is governed by two hard, unforgiving deadlines set by the Internal Revenue Code and Treasury regulations: 45 calendar days to identify your replacement property and 180 calendar days to close on it. Miss either one and the exchange fails, meaning the sale is treated as a fully taxable event.

This article walks through exactly how those clocks work, the rules for a valid identification, the step-by-step timeline, the mistakes that most often blow an exchange, and why Delaware Statutory Trusts (DSTs) have become a common backup plan. It is educational only and is not tax or legal advice — always confirm your specific dates and strategy with your Qualified Intermediary and your CPA before you act.

The Two Deadlines That Define Every Exchange

Both deadlines start ticking on the same moment: the day your relinquished property (the property you are selling) closes. That closing day is "Day 0."

• ›The 45-Day Rule. You have 45 calendar days from the closing of the relinquished property to formally identify your potential replacement property or properties.
• ›The 180-Day Rule. You have 180 calendar days from that same closing to actually acquire (close on) the replacement property.

Two things trip people up. First, these periods run concurrently, not consecutively. The 180-day clock is not 45 + 180. Your 45 days are simply the first 45 days of the same 180-day window. Second, there is a wrinkle on the back end: the replacement property must be acquired by the earlier of 180 days or the due date of your tax return (including extensions) for the year the relinquished property was sold. If you sell late in the calendar year, filing your return before the 180th day would shorten your window — which is why most exchangers who sell in Q4 file an extension to preserve the full 180 days.

Calendar Days Mean Calendar Days

The single most important thing to internalize: these are calendar days, not business days.

• ›Weekends count. Holidays count. There is no "the deadline falls on a Sunday, so it rolls to Monday" grace. If Day 45 lands on a Saturday, Sunday, or Thanksgiving, it is still your deadline.
• ›There are no extensions for being busy, for a lender being slow, or for a deal falling apart.
• ›The only exception is limited relief the IRS grants after a federally declared disaster. When the IRS issues a specific disaster notice, affected taxpayers may get a postponement of the 45- and/or 180-day deadlines. This relief is not automatic and not guaranteed — it applies only when your situation fits the terms of a published IRS notice.

Because the rules are this rigid, treat Day 45 and Day 180 as immovable. Confirm both dates in writing with your Qualified Intermediary the moment your sale closes.

The Qualified Intermediary: You Cannot Touch the Money

A 1031 exchange only works if you never take actual or constructive receipt of the sale proceeds. If the money hits your bank account — even for a day — the IRS treats it as a completed, taxable sale and the exchange is dead.

That is why a Qualified Intermediary (QI), also called an accommodator or exchange facilitator, is required. The QI:

• ›Holds the proceeds from your relinquished property sale in a segregated escrow account.
• ›Is assigned into your sale and purchase contracts so the exchange is properly documented.
• ›Receives your written identification and, at closing, wires the funds directly to buy the replacement property.

Key point: the exchange documents must be in place before the relinquished property closes. You cannot sell, pocket the check, and then decide to do an exchange. Choose a QI early. The QI is not allowed to be your agent — your own attorney, CPA, real estate broker, or employee generally cannot serve as your QI.

The Three Identification Rules

Within your 45 days you must identify replacement property in writing, signed by you, and delivered to your Qualified Intermediary (not merely to your broker or attorney). The identification must unambiguously describe each property — typically by street address or legal description. To keep the identification valid, you must satisfy at least one of three rules:

1. The Three-Property Rule. You may identify up to three properties of any value. This is the most commonly used rule because it is simple and value has no ceiling.

• ›*Example:* You sell for $1,000,000 and identify three replacement properties worth $600,000, $900,000, and $1,200,000. Valid — you named three or fewer, and value does not matter under this rule. You then close on whichever one (or ones) you choose.

2. The 200% Rule. You may identify any number of properties, as long as their combined fair market value does not exceed 200% of the value of what you sold.

• ›*Example:* You sell for $1,000,000. You may identify four, five, or ten properties as long as their total value stays at or under $2,000,000. Identify properties totaling $1,900,000? Valid. Total $2,100,000? You have busted the 200% cap and the identification fails.

3. The 95% Rule. If you blow past both the three-property limit and the 200% cap, you can still be valid only if you actually acquire at least 95% of the total value of everything you identified.

• ›*Example:* You identify twelve properties worth $5,000,000 total against a $1,000,000 sale (way over both prior limits). To be valid you must close on at least $4,750,000 of that identified value. This is a high bar and is rarely relied on intentionally.

You are not required to buy everything you identify — under the first two rules you can walk away from properties you named. But you cannot acquire a property you never properly identified. Identifications can be revoked and replaced in writing before the 45-day deadline; after Day 45 the list is locked.

The Step-by-Step Timeline

Before the sale. Line up your team: Qualified Intermediary, CPA, and real estate counsel. Have the QI prepare the exchange agreement and assignment documents so they are executed before the relinquished property closes. Start scouting replacement property now — 45 days is shorter than it sounds.

Day 0 — Closing of the relinquished property. The QI receives the net proceeds directly. Your two clocks start. Ask the QI to confirm your Day 45 and Day 180 calendar dates in writing immediately.

Days 1–45 — The identification window. Tour, underwrite, and negotiate. Before midnight on Day 45, deliver a signed, written identification to your QI that satisfies one of the three rules. Get written confirmation of receipt.

Days 45–180 — The acquisition window. Perform due diligence, secure financing, and close on the identified property. Remember the "earlier of 180 days or your tax-return due date" limit — file an extension if a late-year sale would otherwise cut your window short. The QI wires the escrowed funds directly to close the purchase.

Common Mistakes That Blow the Exchange

• ›Missing the 45-day identification deadline. The most common failure. There is no cure and no extension outside declared-disaster relief.
• ›A defective identification. Naming four properties under the three-property rule, exceeding the 200% cap, describing a property too vaguely, or delivering the list to the wrong party (your broker instead of the QI).
• ›Touching the funds. Receiving proceeds directly, or setting up the QI relationship after closing, destroys the exchange.
• ›Financing that falls through. If your lender pulls out on Day 170, you still must close by Day 180 — there is no extension. Line up financing early and have a backup.
• ›Buying property you did not identify. You can only close on what is on your Day-45 list.
• ›Late-year timing. Selling in Q4 and forgetting the tax-return-due-date limit, thereby losing part of the 180 days.

Reverse and Improvement Exchanges

Standard exchanges sell first, then buy. Two variations exist for different situations:

• ›Reverse exchange. You acquire the replacement property before selling the relinquished one. Because you cannot hold title to both at once, an "Exchange Accommodation Titleholder" (EAT) parks one property. The same 45-day identification and 180-day completion clocks apply, measured from when the parked property is acquired.
• ›Improvement (build-to-suit) exchange. Exchange proceeds are used to build or renovate the replacement property. Any improvements must be completed and the property received within the same 180-day window to count toward the exchange value. These are more complex and more expensive to structure.

Why DSTs Are Used as a Fast Backup

A Delaware Statutory Trust (DST) is a pre-packaged, professionally managed real estate investment in which you buy a fractional beneficial interest. The IRS has recognized a properly structured DST interest as like-kind replacement property for 1031 purposes.

DSTs are popular as an identification backup for one reason: the 45-day clock. Because DST offerings are already assembled — property acquired, financing in place, documents ready — you can often be placed into one in days rather than months. That makes a DST a practical property to identify on your Day-45 list as a fallback in case your primary deal collapses in due diligence or financing falls through. If your main purchase closes, you may never use the DST; if it does not, you already have a valid, closeable identification in hand and can protect your deferral.

DSTs also help absorb leftover proceeds so you avoid taxable "boot," and they suit investors seeking to exit active management. They are illiquid, carry fees, and are securities sold only to accredited investors — and, like all real estate, they carry risk with no guaranteed returns.

Bottom Line

The 1031 timeline rewards preparation and punishes delay. Engage a Qualified Intermediary before you sell, understand the three identification rules cold, treat Day 45 and Day 180 as fixed calendar dates with no weekend or holiday relief, and keep a fast-closing option like a DST on your identification list as insurance. This guide is educational and not tax or legal advice — confirm your exact dates and strategy with your Qualified Intermediary and CPA before you act.