1031 Exchange Identification Rules: 45 Days, 3 Properties, 200%, 95%
In a deferred 1031 exchange, you must identify your replacement property by midnight of the 45th day after you transfer the property you sold, in a written document you sign and deliver to your qualified intermediary or another proper party to the exchange. You can identify up to three properties of any value, or any number of properties whose combined value is no more than 200% of the value of what you sold. If you identify more than either test allows, the identification still works only if you go on to acquire at least 95% of the value of everything you identified.
These rules come from Treasury Regulation 1.1031(k)-1(c), and they are strict: a late, vague or oral identification doesn’t count. This page explains the mechanics, each of the three tests, how to change your list before day 45, special cases such as property still under construction, and how to build a list that holds up in North Bay markets where good replacement properties are scarce. For the overall structure of an exchange, start with our 1031 exchange guide.
When the 45-day clock starts and stops
The identification period begins on the date you transfer the relinquished property, usually the day the sale closes, and ends at midnight on the 45th day after that. It runs at the same time as the exchange period, which ends on the 180th day or the due date of your tax return for that year, including extensions, whichever comes first. The two periods are not added together.
- Several relinquished properties: if you sell more than one property in the same exchange on different dates, the earliest transfer date starts both clocks.
- Property you close on within 45 days: replacement property you actually receive before the identification period ends is treated as identified.
- Weekends and holidays: the regulation counts calendar days and contains no weekend or holiday extension, so treat day 45 as fixed and deliver your list before it if that day falls on a weekend.
A worked example: a sale that closes on November 2, 2026 has a 45th day of December 17, 2026. Our 1031 deadline calculator counts both dates from any closing date; confirm them with your intermediary.
How to identify a property properly
The regulation sets three requirements for the identification itself.
- In writing and signed by you. The document must be signed by the taxpayer. Alternatively, the replacement property can be identified in a written exchange agreement signed by all parties before the period ends.
- Delivered to the right person. It must be hand delivered, mailed, faxed or otherwise sent before the deadline to the person obligated to transfer the replacement property to you, or to another person involved in the exchange other than you or a “disqualified person,” a term the regulation defines. In practice, most exchangers send it to their qualified intermediary and keep proof of delivery.
- Unambiguous. Real property must be described by a legal description, a street address or a distinguishable name. The regulation’s examples show that a description too vague to pin down a property fails.
Your intermediary will usually supply a form. Use the parcel’s full street address and assessor’s parcel number where you can; for a vineyard or rural parcel without a clear street address, use the legal description from the preliminary title report. Our qualified intermediary guide covers choosing one. Diamond may refer you to partners we work with; you’re free to choose any provider.
You’ll report the identification date on Form 8824. The IRS instructions ask for the date of the written identification on line 5 and the date you received the property on line 6.
The three identification tests
You only have to satisfy one of these. Most exchangers use the first or second and treat the third as a safety net they hope not to need.
| Test | What you can identify | Value measured | Typical use |
|---|---|---|---|
| Three-property rule | Up to three properties, regardless of value | Not relevant | One target and two backups |
| 200% rule | Any number of properties | Their combined value at the end of the identification period can’t exceed 200% of the value of the property you sold | Several smaller properties, or more backups than three |
| 95% rule | Any number, any value | You must acquire at least 95% of the combined value of everything identified; each property is valued as of the earlier of the date you receive it or the end of the exchange period | Rarely planned; it requires closing on nearly everything listed |
A hypothetical example
Suppose you sell a Santa Rosa fourplex for $2,400,000. Under the three-property rule you could identify a $3,000,000 Napa mixed-use building, a $2,600,000 Petaluma apartment building and a $2,450,000 Sonoma commercial building, since value doesn’t matter. Under the 200% rule you could identify five properties, as long as they total no more than $4,800,000.
If you identified four properties totaling $6,000,000, you’d have exceeded both limits. The identification would then hold only if you acquired at least $5,700,000 of that list; otherwise only property you had already received by day 45 would count.
Incidental property
Property that is usually transferred along with a larger item, such as furnishings included in the sale of a rental, isn’t treated as a separate property for the identification tests if its total value is 15% or less of the larger property’s value. Since 2018 only real property qualifies for like-kind treatment, so anything that isn’t real property may still be taxable boot even when it doesn’t count against your list. See our guide to boot and partial exchanges.
Changing your list: revocation before day 45
“An identification of replacement property may be revoked at any time before the end of the identification period,” the regulation says. The revocation must be in a written document you sign and send to the same person who received the identification. If the identification was made in the exchange agreement itself, the revocation must be a written amendment or a writing sent to all parties.
Two practical consequences. An oral revocation doesn’t work; the regulation’s own examples say so. And after midnight on day 45 the list is closed, so you can’t swap in a property that came to market on day 46.
Property under construction or to be improved
You can identify property that hasn’t been built yet or will be improved, but the identification has to give as much detail about the construction as is practicable at the time. What you receive by day 180 must be substantially the same property you identified, with ordinary variations in construction disregarded. Real property that isn’t finished by the time you receive it counts only to the extent it is real property under local law, so build in time. Our guide to improvement exchanges explains how exchange funds can pay for the work, and the reverse exchange guide covers buying before you sell.
Disaster postponements
The deadlines can move only in narrow circumstances. Revenue Procedure 2018-58 lists the 45-day identification period and the 180-day exchange period among the time-sensitive acts the IRS may postpone after a federally declared disaster. Whether you qualify, and for how long, depends on the IRS notice or news release for that disaster, which defines the affected taxpayers. Fire seasons in Sonoma and Napa make this worth knowing, but don’t plan around it; ask your intermediary and tax adviser to confirm in writing that a postponement applies to you.
Building a list that holds up in the North Bay
In Sonoma, Napa and Marin, the hard part is usually finding enough property that fits, not filling in the form. Some practices that help:
- Start looking before the sale closes. Tour candidates during the sale escrow so day 1 of the identification period isn’t day 1 of your search.
- Use all three slots. A primary target plus two genuine backups is the most common structure. A backup should be a property you would actually buy.
- Get the primary under contract early. A signed purchase agreement with contingency dates that end well before day 180 gives you a clear read on whether the backups will be needed.
- Choose the 200% rule for several smaller buys. If you plan to split proceeds across, say, a duplex and two single-family rentals, add up the values first.
- Look off-market as well as on the MLS. Diamond reaches owners through its own client database and targeted off-market campaigns, which can surface a property that isn’t listed. We can’t promise access to other brokerages’ private listings. Our post on finding off-market homes explains how that search works.
- Know your fallback. Some exchangers list an interest in a Delaware statutory trust as one of their three properties. Whether a particular offering suits you is a question for your adviser, not your agent.
Vineyard and ranch exchanges raise extra questions about which assets are real property; see our guide to 1031 exchanges for vineyards and ranch land. If the deal includes cash out, California withholding can apply to the boot, as explained in our Form 593 guide.
Questions people ask
What are the 1031 exchange identification rules?
You must identify replacement property in a signed, written document delivered to your intermediary or another proper party by midnight of the 45th day after your sale. You may identify up to three properties of any value, or any number totaling no more than 200% of the value sold; otherwise you must acquire 95% of what you identified.
Does the 45-day period include weekends and holidays?
Yes. The regulation counts calendar days and has no weekend or holiday extension, so plan to deliver your list before the deadline if day 45 is a Saturday, Sunday or holiday.
Can I identify more than three properties?
Yes, under the 200% rule, if the combined value of all identified properties at the end of the identification period is no more than 200% of the value of the property you sold. Beyond that, the 95% rule applies.
Can I change my identified properties?
Before the 45th day ends, yes: revoke the earlier identification in a signed writing sent to the person who received it, then deliver a new one. After day 45, the list can’t be changed.
Who do I send my 1031 identification to?
To the person obligated to transfer the replacement property to you, or to another person involved in the exchange who isn’t you or a disqualified person. Most exchangers send it to their qualified intermediary and keep proof of delivery.
What happens if I miss the 45-day deadline?
Property not identified on time, and not already received by day 45, can’t complete the exchange. The sale is then generally taxable, and California withholding rules for a failed exchange can apply. Talk to your intermediary and tax adviser immediately.
Do I have to buy every property I identify?
No, if you stayed within the three-property or 200% limits; you can buy just one of them. Only if you exceeded both limits must you acquire at least 95% of the total value identified.
This is general information, not legal or tax advice; talk to a CPA, tax attorney or your qualified intermediary about your situation.
If your sale has closed or is about to, and you need help finding and contracting replacement property inside the 45 days, talk to us through our investment property services.
Sources & notes
- Cornell Law School LII: 26 CFR 1.1031(k)-1, treatment of deferred exchanges
- Internal Revenue Service: Instructions for Form 8824, Like-Kind Exchanges (2025)
- Internal Revenue Service: Revenue Procedure 2018-58 (time-sensitive acts postponed for disasters)
- Franchise Tax Board: 2026 Instructions for Form 593 (exchanges and boot)
Last reviewed October 2026 by Matthew Martinez.
