The 45-day identification window in a 1031 exchange starts at closing, and every calendar day counts.
The 45-day identification window in a 1031 exchange starts at closing, and every calendar day counts.

The 45-day identification window in a 1031 exchange starts at closing, and every calendar day counts.
A 1031 exchange gives investors 45 calendar days to identify a replacement property in writing, and the clock starts the day the relinquished property transfers — not when a buyer is found or a contract is signed. Weekends, holidays and December 25 all count, and day 45 does not move to Monday if it lands on a Saturday, according to IRS Publication 544.
"The deadline was never really the problem. It is fixed, published and knowable," said Carl E. Sera, president and managing principal at Sera Capital Management, a fee-only fiduciary firm. "The problem was that the most consequential financial decision got made during the seven days when there was the most pressure and the least information."
The identification must be in a signed writing, describe the property unambiguously and go to a permitted party in the exchange. A conversation with a broker does not count, and neither does a note to your own accountant or attorney, whom the rules treat as disqualified recipients. Investors may identify up to three properties at any value, or any number whose combined fair market value does not exceed twice the value of what was sold — the 200% rule — or any number at any value if they actually acquire at least 95% of the total value identified.
The stakes are a failed exchange and a capital gains tax bill. If an investor identifies four properties and blows past the 200% ceiling without satisfying the 95% rule, the extra identifications do not simply fall away — the investor can be treated as having identified nothing at all, and the exchange can fail. That discovery typically comes in April, from a CPA, about a decision made in October.
The exchange period is not automatically 180 days. It ends on the earlier of day 180 or the due date of the return, including extensions. A November 15 closing puts day 180 in mid-May, but filing the return on April 15 without an extension ends the exchange period on April 15, cutting roughly a month of runway. The fix is usually Form 4868, filed by the original due date, which moves the filing deadline to October 15 and pushes the exchange period past day 180. An extension buys more time to file, not more time to pay — any tax owed is still due on the original date — and filing the return early blocks the extension. The right form depends on how the return is filed, whether as an individual, a partnership or a corporation, so it should be confirmed with a CPA.
The expensive trap is psychological. As the deadline approaches, investors grow more certain not because the property improved but because the cost of walking away became visible. Contingencies get waived that would have mattered in any ordinary purchase, capital expenditures get underestimated, and debt gets replaced with expensive or restrictive financing. Sera recommends six steps before the relinquished property closes: model the federal and state tax consequences including depreciation recapture; set the reinvestment range and decide whether some cash should be intentionally retained and taxed; decide which structures are on the table; write down underwriting standards; prepare more than one path with a backup you would actually own; and assemble the team before the sale, since the qualified intermediary must be engaged before closing.
Delaware statutory trusts, or DSTs, can come together quickly because there is no purchase price to negotiate or property-level financing to arrange, which is why they often appear late in an exchange. Chosen deliberately as part of a plan made before the sale, a passive replacement can be the right answer; chosen on day 43, it is whatever was available.
The rules cited here come from IRS Publication 544 and the Treasury regulations governing deferred exchanges, and tax law changes over time — investors should verify the current requirements against the latest official IRS guidance before acting. This article is for informational purposes only and does not constitute investment, tax or legal advice.