The two clocks · IRC §1031 deadlines

45 days to name it.
180 to close it.

Both clocks start the day your sale closes, and they run at the same time — not one after the other. They’re calendar days, weekends and holidays included. There are no extensions for being busy, for a deal falling through, or for not knowing the rule existed. This page is the whole timeline in plain English, including the identification rules almost nobody explains until it’s too late to use them.

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Day 45
to identify replacement property in writing, delivered to the intermediary
Day 180
to close — or your tax-return due date including extensions, whichever comes first
Concurrent
the two clocks run together. Day 45 means 135 days remain, not 180
No extensions
absent a federally declared disaster. Not for financing, not for a failed deal
The trap in the arithmetic

Day 45 is not a third of the way through.

Most people hear “45 days and 180 days” and picture two phases: a month and a half to shop, then four months to close. That is not how it works. Both periods begin on the same day — the closing of the property you sold — and run simultaneously.

So the moment you hit day 45 and hand over your identification, you have already used a quarter of your total runway. Only 135 days remain to finance, inspect, negotiate and close on a property you may have first walked through two weeks ago. In a slow financing market that is not a comfortable margin, and it is the single most common reason an exchange that cleared the identification deadline still fails at the end.

The 45-day deadline doesn’t decide whether you find a property. It decides whether you had already found it before you sold.

This is the entire argument for lining up replacement candidates before the relinquished property goes under agreement. It is not about being organized. It is about the fact that the clock is shorter than it sounds.

The replacement backstop

Which is why we put a number on it. Agree on your criteria in writing before you list, and by day 20 you have a written slate of at least three qualifying candidates — or we cut our commission on your sale by half a percent. We can’t promise the market cooperates. We can promise you aren’t sitting at day 40 with an empty list. How the backstop works →

The identification rules

You must pick one of three rules — and stay inside it.

Identification isn’t a phone call or a handshake. It is a written notice, signed by you, describing the property unambiguously, delivered to your qualified intermediary before midnight on day 45. And what you are allowed to identify is governed by one of three rules. Exceed the one you’re relying on, and the identification can fail entirely.

RULE 01
The safe default

The Three-Property Rule

Identify up to three properties, at any value, with no ceiling. You don’t have to buy all three — you can close on one, two, or all of them. This is what most straightforward exchanges use, and unless there’s a reason to do otherwise, it’s the rule we plan around.

RULE 02
When you need more options

The 200% Rule

Identify more than three properties, but their combined fair market value cannot exceed 200% of what you sold. Sell for $1M and you can identify any number of properties totaling up to $2M. Useful when you want backup options on smaller assets.

RULE 03
The one you don’t want to need

The 95% Rule

If you blow through both rules above, the exchange only survives if you actually acquire 95% of the total value of everything you identified. This is a rescue provision, not a strategy. If you’re relying on it, something upstream went wrong.

FORM
How it has to be written

Unambiguous description, in writing, signed

A street address or legal description — not “a duplex in Quincy.” For property still under construction, the description has to include what will be built. Delivered to the QI (or another party to the exchange), not to your attorney’s file or your own records.

The revocation window nobody uses

You may revoke and replace an identification at any time before day 45 ends, in writing, the same way you made it. After midnight on day 45 the list is frozen — you cannot add, swap, or substitute, even if a deal collapses the next morning. Which means the practical deadline for discovering a problem with your list is before the deadline, not on it.

The 180 days

The second clock has a trap in it too.

The exchange period is 180 calendar days from your sale — or the due date of your tax return for the year the sale happened, including extensions, whichever is earlier. That second half of the sentence is where people get caught.

01
The ordinary case

You get the full 180

Sell in the first three quarters of the year and the 180-day period expires before your return is due. Nothing to think about.

02
The Q4 problem

A late-year sale can shorten your window

Sell in, say, November and your 180 days would run past April 15. Unless you extend your return, the exchange period ends on the filing deadline instead — potentially cutting a month or more off the time you thought you had.

03
The fix

File the extension

Extending the return preserves the full 180 days. It is a routine step, it costs nothing, and forgetting it is a completely avoidable way to lose weeks of runway. This is exactly the sort of thing that gets missed when the CPA finds out about the sale in March.

04
Both, not either

You must close AND have identified

Hitting day 180 with a closing scheduled for day 181 is a failed exchange. So is closing on day 100 on a property that was never properly identified by day 45. Both conditions have to hold.

What we actually do about it

We work the clock backwards, starting before you list.

Every deadline on this page is fixed and public. The only variable is how much of the work happens before the clock starts — which is the entire design of how we run an exchange.

Before you list

Candidates identified early

Our brokerage is sourcing replacement options while your property is still being prepped for market, so day 45 is a decision you make rather than a scramble you survive.

Before you close

Financing conversations opened

Lender conversations start at the beginning, not on day 44. Financing failing inside the 180 is one of the most common late-stage exchange deaths, and it is largely a lead-time problem.

At closing

Proceeds go straight to the QI

An independent qualified intermediary receives the funds directly. If the money touches your account, even briefly, the deferral is gone — there is no fixing it afterward.

Through both clocks

Every checkpoint tracked and flagged

You get told where you are in the calendar and what has to happen next, in writing, rather than discovering the date in a panic.

Deadline questions

The ones that come up every time.

What if day 45 lands on a weekend or a holiday? +
It still counts. These are calendar days, and the deadline does not roll forward to the next business day the way some filing deadlines do. If day 45 is a Sunday, your identification has to be delivered by the end of that Sunday. Plan the delivery mechanics ahead of time.
Can I change my identification after I submit it? +
Yes, but only until the end of day 45. Revocation has to be in writing and delivered the same way the original identification was. Once the 45th day ends, the list is locked — you cannot substitute a new property even if one of yours falls through on day 46.
What happens if I miss the deadline? +
The exchange fails and the sale is treated as a straightforward taxable sale — capital gains, depreciation recapture, and any applicable state tax all become due for that year. There is no partial credit and no appeal for missing it. The only recognized relief is for federally declared disasters, which the IRS announces specifically.
Can I get an extension if my financing falls through? +
No. Financing problems, failed inspections, a seller backing out, or a deal dying at the last minute are not grounds for extending either clock. This is precisely why we identify more than one candidate where the rules allow it, and why lender conversations start early rather than late.
I sold in the fourth quarter. Do I really need to extend my return? +
If your 180-day window would otherwise run past your filing deadline, then yes — extending is what preserves the full period. It is a simple step and skipping it can quietly cost you weeks. Anyone coordinating your exchange should be raising this the moment a Q4 closing is on the calendar.
Does the clock start at signing or at closing? +
At closing — specifically the transfer of the relinquished property. Going under agreement does not start it. But going under agreement is when the useful work should already be underway, because by then you can see the closing date coming.
The free exchange review

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