Deadlines · not tax or legal advice

The 1031 exchange timeline (45 / 180)

The Code does not give a 1031 “grace period” for weekends. Identification is generally 45 days after you transfer the relinquished property. Receipt of replacement property is generally the earlier of 180 days after that transfer or the due date of your return, including extensions, for the year of the transfer. Miss either clock and §1031(a)(3) treats the property as not like-kind for that exchange. This page restates the cited text. It is not a calendar for your file.

Identification period — 45 days

IRC §1031(a)(3)(A): property received is treated as not like-kind if it is not identified as property to be received in the exchange on or before the day which is 45 days after the date the taxpayer transfers the relinquished property. Treas. Reg. §1.1031(k)-1(b)(2)(i) names that window the identification period. The period begins on the date the taxpayer transfers the first relinquished property and ends at midnight of the 45th day.

How you identify — writing, signature, delivery, the 3-property / 200-percent / 95-percent rules — isa separate page. This page is only the clock.

Exchange period — 180 days or the return due date

IRC §1031(a)(3)(B): property received is treated as not like-kind if it is received after the earlier of (i) the day which is 180 days after the relinquished transfer, or (ii) the due date (determined with regard to extension) for the transferor’s return for the taxable year in which the relinquished transfer occurs. Treas. Reg. §1.1031(k)-1(b)(2)(ii) names that window the exchange period.

Filing the return on April 15 without an extension can cut the exchange period shorter than 180 days when the sale was late in the year. Extending the return can preserve the 180-day end — that is what “with regard to extension” is doing in the statute. Ask counsel before you treat a draft return as a deadline tool.

Weekends, holidays, disasters

The identification and exchange periods in the cited Code and regulation text are calendar-day counts. They do not, on the face of those sections, roll to the next business day because day 45 is a Sunday. Some other Code sections do that. §1031(a)(3) as fetched does not.

Federally declared disasters can produce IRS relief notices that postpone certain 1031 acts. Those notices are publication- and date-specific. This page does not invent a standing weekend or disaster exception. If a notice applies to your county and your dates, counsel has to match it to your file.

Reverse and improvement files still have clocks

A reverse or parking exchange uses an exchange accommodation titleholder under Rev. Proc. 2000-37, limited by Rev. Proc. 2004-51. Improvement / construction work has to be received as replacement property before the exchange period ends if you want that work in the exchange. Definitions and failure modes:forward vs reverse vs improvement.

FAQ

When does the 45-day identification period start?

IRC §1031(a)(3)(A) runs the identification deadline from the date the taxpayer transfers the relinquished property. Treas. Reg. §1.1031(k)-1(b) calls that the start of the identification period. It is 45 days, including weekends and holidays. There is no automatic weekend extension in the cited Code or regulation text.

Is the exchange period always 180 days?

No. IRC §1031(a)(3)(B) ends the exchange period on the earlier of 180 days after the relinquished transfer or the due date (including extensions) of the taxpayer’s return for the year of that transfer. If you file the return without extending, the earlier date can be the filing deadline, not day 180.

Do reverse / parking exchanges use different clocks?

The delayed-exchange 45/180 clocks in §1031(a)(3) are about identification and receipt of replacement property after a relinquished transfer. Reverse and parking structures sit primarily in Rev. Proc. 2000-37, as limited by Rev. Proc. 2004-51, with their own QEAA timing. See forward vs reverse vs improvement. Do not assume the delayed clocks are the only clocks on a parked file.

Sources

26 U.S.C. §1031(a)(3) — law.cornell.edu/uscode/text/26/1031. Identification and exchange periods. Accessed 2026-09-11.
Treas. Reg. §1.1031(k)-1(b) — law.cornell.edu/cfr/text/26/1.1031(k)-1. Identification period; exchange period. Accessed 2026-09-11.
Rev. Proc. 2000-37 — irs.gov/pub/irs-drop/rp-00-37.pdf. Parking / QEAA. Accessed 2026-09-11.
Rev. Proc. 2004-51 — irs.gov/pub/irs-drop/rp-04-51.pdf. Limitation on 2000-37. Accessed 2026-09-11.

Editorial access date: 2026-09-11. This page is not tax, legal, or investment advice.