A 1031 exchange lives or dies by its calendar. Two deadlines start the day you sell, run at the same time, and have no do-overs — miss either one and the whole exchange collapses into a taxable sale. This is a plain-English walkthrough of the 1031 exchange timeline: when each clock starts, exactly what you have to do by when, and the Maryland and DC timing details most guides skip.
The two deadlines at a glance
Both clocks start on the day you transfer (sell) your relinquished property — Day 0 — and they run concurrently, not back-to-back:
- 45 days to identify your replacement property (or properties) in writing.
- 180 days to close on the replacement — or your tax-return due date including extensions, whichever comes first.
They are calendar days, including weekends and holidays. There is no "next business day" grace period and, outside a federally declared disaster, no extensions.
Day 0: the clock starts
The timeline begins the day the sale of your relinquished property closes and the proceeds go to your qualified intermediary (QI) — not to you. If the money touches your account, the IRS treats it as "constructive receipt" and the exchange is dead before it starts. Line up the QI before closing, not after.
The 45-day identification period
By 11:59 p.m. on Day 45 you must deliver a written, signed identification of your replacement property to your QI. The description has to be specific — a street address or legal description, not "a commercial building in Baltimore." Key points:
- It must be in writing and signed — a phone call or a verbal nod doesn't count.
- It goes to the QI (or another party to the exchange), not just your agent or attorney.
- Weekends and holidays are included in the 45 days. If Day 45 is a Sunday, it's still Day 45.
- Once the 45 days pass, your identification is locked — you generally can't swap in a property you didn't list.
The identification rules (3-property / 200% / 95%)
Your written identification has to fit one of three rules: the three-property rule (up to three, any value), the 200% rule (any number, combined value ≤ 200% of what you sold), or the 95% rule (more than that, but you must acquire at least 95% of the identified value). Most investors use the three-property rule. Full detail is in our 1031 Exchange Maryland & DC guide.
The 180-day exchange period
After the 45-day window closes, you have the remainder of the 180 days — about 135 more days — to actually close on and take title to a property you identified. Two things trip people up:
- The 180 days include the first 45 — it is not 45 plus 180.
- If your tax-return due date (including extensions) falls before Day 180, the exchange period ends then. A late-year sale is the classic trap: sell in November and your return due date can cut the window short unless you file an extension to preserve the full 180 days.
What happens if you miss a deadline
There is no partial credit. Miss the 45-day identification or the 180-day closing and the exchange fails — the sale becomes fully taxable in that year, including any depreciation recapture. The deadlines are statutory, so a QI, attorney, or CPA cannot extend them for you. The only exceptions are federally declared disaster postponements. Build in buffer; don't aim to close on Day 179.
Maryland & DC timing specifics
Two local timing items that national guides leave out:
- Maryland (Form MW506AE): Maryland withholds tax from nonresident sellers at settlement (8% for individuals, 8.25% for entities). In a valid 1031 there's no current Maryland tax due — but you must file Form MW506AE ahead of settlement to get a certificate reducing or eliminating that withholding. File late and your capital is tied up until you recover it on a later return.
- Washington, DC: DC conforms to the federal deferral, but DC transfer and recordation taxes are due at closing and are not deferred by the exchange. Budget for them as a real cost of the deal.
A sample timeline
To make it concrete, here's how a clean exchange runs:
- Day 0 — You sell your relinquished property; proceeds go to the QI.
- By Day 45 — You deliver a signed, written identification of your replacement property to the QI (MD sellers: MW506AE already filed before settlement).
- By Day 180 — You close on an identified property and take title; the QI releases the funds to complete the purchase.
A note on reverse and build-to-suit exchanges
The 45/180 clocks apply to a standard (delayed) exchange. Reverse exchanges (you buy the replacement first) and build-to-suit/construction exchanges follow the same 45/180 framework but add their own structuring and are more complex — work them through with a QI and CPA early.
Frequently asked questions
Can the 45-day or 180-day deadlines be extended?
No — they're set by statute. The only exceptions are IRS postponements for federally declared disasters. Filing a tax-return extension doesn't extend the 180 days; it just prevents your return due date from cutting the window short.
Do weekends and holidays count in the 45 and 180 days?
Yes. They're calendar days. If Day 45 or Day 180 lands on a weekend or holiday, the deadline still stands — there's no automatic extension to the next business day.
Can I identify more than three replacement properties?
Yes, under the 200% rule (any number, combined value up to 200% of what you sold) or the 95% rule (more than that, if you acquire at least 95% of the identified value). Most investors stay within the simpler three-property rule.
When does the 180-day clock actually start?
On Day 0 — the day your relinquished property sale closes — the same day the 45-day clock starts. The periods overlap; the 180 days are not added on after the 45.
Planning an exchange in Maryland or DC? You can browse 1031 exchange listings on MeetTheMinds — commercial and investment properties listed by sellers for exchange investors — and read the full Maryland & DC 1031 guide for the complete rules.
This article is general information, not tax or legal advice. 1031 deadlines are strict and fact-specific. Always confirm your situation with a qualified CPA, tax attorney, and a qualified intermediary before acting.