Real Estate Tax Calc
Why identification rules matter
In a 1031 exchange, you must deliver a written identification of potential replacement properties to your qualified intermediary within 45 days of the sale. The IRS doesn't allow unlimited identification — you must follow one of three approved rules, or the exchange fails.
The 3-property rule
The 3-property rule lets you identify up to three properties regardless of their total fair market value. This is the most commonly used rule — it gives you backup options without any value constraint, and the simplicity makes it the default choice for most investors.
The 200% rule and 95% rule
The 200% rule lets you identify any number of properties, as long as their combined fair market value doesn't exceed 200% of the value of the relinquished property. The 95% rule imposes no value cap but requires that you actually close on 95% of the total FMV you identified — an extremely high bar rarely used in practice. Stick with the 3-property rule unless you specifically need more than three options.
How the 45-day clock is counted
The identification period is 45 calendar days starting the day after the relinquished property closes. Weekends and holidays are included, and the deadline is firm — there is no discretionary extension, and even the 45th day falling on a Saturday, Sunday, or holiday does not push it out (unlike ordinary tax filing deadlines). The only relief is an IRS-declared federally recognized disaster, which can toll both the 45-day and 180-day periods. Because the clock is so unforgiving, most investors line up candidate properties before they close on the sale, not after.
What a valid identification must contain
The identification must be in writing, signed by you, and delivered before midnight on day 45 to a party involved in the exchange — in practice your qualified intermediary. Delivering it to your own attorney, real estate agent, or accountant generally does not count, because they are considered disqualified persons or agents. Each property must be described unambiguously: a legal description or a street address is sufficient; a vague reference like a certain building in downtown is not. For property still to be built or improved, describe it as it will exist when completed. You may revoke and re-identify as many times as you like, but only within the 45-day window — once the period closes, your list is locked.
The 3-property rule in depth
Under the 3-property rule you may name up to three replacement candidates with no limit on their combined value, and then close on any one, two, or all three. This is why it is the default choice: it lets you carry backup options in case your first choice falls through in due diligence or financing, without any appraisal math. If you only ever intend to buy a single replacement, identifying two or three fallbacks under this rule is cheap insurance against the 45-day deadline.
The 200% rule with an example
Choose the 200% rule when you want to spread proceeds across more than three properties — for example, several condos, a portfolio of small rentals, or fractional Delaware Statutory Trust (DST) interests. You can identify unlimited properties as long as their total fair market value stays at or below 200% of what you sold. Sell for $600,000 and you may identify any number of replacements whose combined FMV does not exceed $1,200,000. Overshoot that ceiling and, unless you satisfy the 95% rule, the IRS treats you as having identified nothing — a failed exchange.
Common mistakes that blow up an identification
The exchange collapses over avoidable errors: missing the 45-day deadline by even a day; identifying four or more properties while relying on the 3-property rule; exceeding 200% of value under the 200% rule; describing a property too vaguely to pin down; delivering the notice only to your own agent instead of the qualified intermediary; or relying on an oral or unsigned identification. Any one of these can convert a tax-deferred exchange into a fully taxable sale, so have the intermediary confirm receipt of a written, signed, correctly-scoped list.
How the 45-day and 180-day clocks interact
The 45-day identification window runs concurrently with the 180-day exchange period — both start the day after you close the relinquished property, and the 180 days is not added to the 45. So once you identify on day 45, you have the remaining time up to day 180 to actually close on a replacement. There is a second trap: the deadline is 180 days or the due date of your tax return (including extensions) for the year of the sale, whichever is earlier. An exchange that straddles year-end can be cut short unless you file an extension to preserve the full 180 days. Miss the closing deadline and even a perfect identification produces a fully taxable sale.
Identifying property to be built or improved
In a construction or build-to-suit exchange, you can identify property that does not yet exist in finished form — but the identification must describe it as it will be when completed, including the underlying land by legal description and enough detail about the planned improvements (square footage, general specifications) to make it unambiguous. You must receive substantially the same property that was identified, and any improvements must be completed and the property received within the 180-day window; work finished after day 180 does not count toward the value you receive. These exchanges are exacting and are almost always run through an exchange accommodation titleholder.
Identifying DST, TIC, and fractional interests
Fractional ownership counts as identifying real property, which is why Delaware Statutory Trust (DST) interests and tenant-in-common (TIC) shares are popular 1031 replacements — especially as backups under the 3-property rule. Describe the specific percentage or beneficial interest in the identified property, not just the sponsor or offering. Because a DST interest can often close quickly, investors frequently identify one as a fallback alongside a primary target, ensuring they can complete some exchange within 180 days even if the main deal falls through in due diligence.
How the 200% value cap is measured
When you rely on the 200% rule, value is measured at fair market value as of the end of the identification period — day 45. In practice the contract or expected purchase price is a reliable proxy, and staying comfortably under the 200% ceiling avoids any dispute. If you are near the limit, err conservative: pull a property off the list rather than risk breaching the cap, because exceeding it is treated as identifying nothing at all (absent the 95% rule) and voids the deferral entirely.
State-level considerations
Most states follow the federal 1031 rules, but a few add wrinkles. Several impose clawback provisions that recapture state tax on gain originally deferred in that state when you later sell an out-of-state replacement, and some require you to file annual reports tracking the deferred gain. A handful of states also mandate nonresident withholding at the sale closing. None of these change the federal 45-day and 200%/3-property identification mechanics, but they affect the after-tax result — confirm your state's treatment before exchanging across state lines.
Practical tips for a clean identification
A few habits keep the identification bulletproof. Line up candidates before you close the sale, because the 45-day clock is unforgiving and good properties take time to find under contract. Put more properties under letter of intent than you expect to buy, so a failed inspection does not leave you with a single fragile option. Send the written, signed identification to your qualified intermediary well before day 45 — not on the last afternoon — and get written confirmation of receipt. Use unambiguous descriptions (full street address or legal description, plus the specific interest for a DST or TIC). And decide up front which rule you are using, so you do not accidentally over-identify.
Reporting the exchange on Form 8824
Once the exchange closes, it is reported on Form 8824 for the tax year the relinquished property was sold. The form captures the dates that prove you met the 45-day identification and 180-day closing deadlines, the values of the relinquished and replacement properties, any boot received, and the deferred gain that rolls into your new basis. Keep your identification letter, the intermediary's receipt confirmation, and both closing statements with your tax records — if the timing of your identification is ever questioned, that dated paper trail is what substantiates that the exchange was valid.
Frequently asked questions
How many properties can I identify in a 1031?
Under the 3-property rule, up to 3 — regardless of value. Under the 200% rule, any number with combined FMV at or below 200% of the sale price.
Must I close on every identified property?
No. You must close on at least one within 180 days. Identifying up to 3 gives you backup options.
When does the 45-day identification clock start?
The day after the relinquished property closes. It runs 45 calendar days including weekends and holidays, with no extension except for IRS-declared disasters.
Can I change my identification after submitting it?
Yes — you may revoke and re-identify in writing as often as you like, but only before the 45-day period ends. After day 45 your list is final.
What happens if I identify too many properties?
Unless you meet the 95% rule, over-identifying is treated as if you identified no property at all, and the exchange fails — making the sale fully taxable.
Who do I deliver the identification to?
Generally your qualified intermediary. Delivery to your own attorney, agent, or accountant usually does not satisfy the requirement.
What is the 180-day rule?
You must close on a replacement property within 180 days of selling the relinquished property — or by your tax return due date (including extensions) for that year, whichever comes first. It runs concurrently with, not on top of, the 45-day identification window.
Sources
Educational information and estimates only. Not tax advice. Tax rules change and vary by situation; consult a qualified tax professional before acting.