In this guide
- Before day zero: the deadline nobody counts
- Day 0: closing day mechanics
- Days 1–45: the identification window
- The three identification rules
- Days 46–180: closing the replacement
- The tax-return trap that shortens 180 days
- The only real extension: disaster relief
- The whole timeline in one table
- Frequently asked questions
Before day zero: the deadline nobody counts
The 45 and 180-day clocks get all the attention, but the deadline that quietly kills more exchanges than either comes first: your exchange must be set up before your sale closes. The qualified intermediary must be engaged, the exchange agreement signed, and the closing instructed to send proceeds directly to the intermediary. If the money touches your account — a day, an hour — you have constructive receipt under Treas. Reg. §1.1031(k)-1(f), and there is no exchange to save. No intermediary can paper over money you already received.
The second pre-closing task is strategic: start hunting replacement property before you list. Forty-five days is brutally short in any market; sellers who begin the search at closing spend half the window discovering what they don't want. The exchangers who look calm at day 40 are the ones who had three candidates before the sale sign went up — and if you find the perfect property before your sale even closes, that's not a crisis, it's a reverse exchange.
Day 0: closing day mechanics
The day the relinquished property transfers is day zero, and three things must happen correctly: the deed records, the proceeds wire from the closing table to the intermediary's segregated exchange account (never through yours), and you note the two dates that now govern your next six months — midnight ending day 45, and midnight ending day 180. Both are computed from this transfer date under §1031(a)(3). Selling multiple properties in one exchange? The clocks run from the first closing — a detail that compresses everything when sales are staggered.
Days 1–45: the identification window
Identification is a formality with teeth. It must be in writing, signed by you, unambiguous (street address or legal description — for a DST interest, the trust name and your percentage), and delivered by midnight of day 45 to your intermediary or another party to the transaction who isn't your agent. Email to the QI is standard practice. You can revoke and re-identify freely — in writing, same formalities — until day 45; after that, the list is carved in stone. Property already closed within the 45 days counts as identified automatically.
The three identification rules
| Rule | What it allows | Who uses it |
|---|---|---|
| Three-property rule | Up to 3 properties, any combined value; close on any of them | Nearly everyone — the default |
| 200% rule | Any number of properties if combined value ≤ 200% of what you sold | Diversifiers splitting into several smaller assets or multiple DSTs |
| 95% rule | Any number, any value — if you actually acquire ≥ 95% of the total value named | Rare; effectively "buy almost everything you listed" |
Strategy inside the rules: use all three slots. A common pattern is two real candidates plus a DST as the third — naming it costs nothing, and because fractional interests close in days, it converts a collapsed primary deal from a blown exchange into a Tuesday. Violate every rule — name four properties worth 300% and buy one — and the identification fails entirely, which makes the arithmetic worth checking twice before day 45. The identification rules guide covers each rule's traps, the exact writing requirements, and the five mistakes that void exchanges.
Days 46–180: closing the replacement
You must receive the replacement property — deed transferred, not merely under contract — by day 180, and it must be property from your identification list (substantially the same as identified). The middle weeks are ordinary deal work: contracts, diligence, financing, with your intermediary wiring exchange funds to each closing. Buying multiple replacements? Each must close inside the window; there's no partial credit for a deal in escrow on day 181. Anything unspent when the period ends comes back to you as taxable boot.
The tax-return trap that shortens 180 days
The exchange period is the earlier of 180 days or the due date of your tax return for the year of the sale, including extensions — §1031(a)(3)(B). Close your sale in late October or later and the following April 15 lands before day 180: your window silently ends on tax day unless you file an extension (Form 4868 or 7004). Filing the extension restores the full 180 days — you don't have to use the extra filing time, just obtain it before filing the return. Every November and December exchanger needs this conversation with their CPA in the same week the sale contract is signed; it is the cheapest fix on this entire page and the most commonly missed.
The only real extension: disaster relief
There is exactly one source of extra time: federally declared disaster relief under Rev. Proc. 2018-58, which can postpone 45-day and 180-day deadlines for affected taxpayers when the IRS issues a qualifying notice — the mechanism used broadly during COVID and after hurricanes and wildfires. It applies only per the specific IRS notice for the specific disaster. Everything else — deals that fell through, illness, title problems, a lender's delay — extends nothing. Plan as if no relief exists, because for you it probably won't.
The whole timeline in one table
| When | What must happen | Failure mode |
|---|---|---|
| Before listing | Replacement search begins; CPA consulted on timing | Half the 45 days wasted discovering the market |
| Before closing | QI engaged, exchange agreement signed, closing instructed | Constructive receipt — exchange dead on arrival |
| Day 0 | Sale closes; proceeds wire to QI; clocks start | Funds touch your account |
| Days 1–44 | Tour, negotiate, contract; revise ID list freely in writing | Drift — the window feels longer than it is |
| Day 45 | Signed written ID delivered to QI (3-property / 200% / 95%) | Missed or defective ID — exchange fails, no cure |
| Days 46–179 | Diligence, financing; QI funds each closing | Deal collapse with no backup identified |
| Day 180* | All replacement property received; exchange complete | *Or tax day, if earlier and no extension filed |
| Next filing | Form 8824 reports the exchange | — |
Your own dates — with weekend flags and the return-due-date truncation computed automatically — take thirty seconds in the deadline calculator. And if the property you're selling sits in a partnership with divided partners, the timeline above has a prequel that starts much earlier: the drop and swap.