1031 exchange deadlines: the 45-day and 180-day rules

When does the exchange clock start?

The rules measure the identification and exchange periods from the transfer of the relinquished property. They do not start when you first contact an adviser or find replacement property. Where multiple relinquished properties form part of the same exchange, the timing rules require particular care. Confirm the controlling transfer date with your qualified intermediary.

Before closing, make sure your exchange agreement and handling of proceeds are arranged. Receiving or controlling sale proceeds can undermine a deferred exchange. A deadline calculator is only a planning aid; it cannot validate an exchange structure or repair a transaction that was set up incorrectly.

What must happen within 45 days?

Replacement property generally must be identified in a signed written document delivered to an appropriate person involved in the exchange, as the regulations require. A personal wish list or an informal conversation is not a substitute for proper identification. Ask the qualified intermediary how to describe each property accurately and document timely delivery.

The rules also limit identification of multiple replacement properties. The three-property rule and alternative value-based rules have different conditions. Do not assume you can list an unlimited number of backups. Have the intermediary and your tax adviser review the identification strategy, including any fractional DST interest.

Why can the completion deadline be shorter than 180 days?

The exchange period ends at the earlier of the 180th day or the due date, including extensions, for the federal income tax return covering the transfer year. A late-year sale can therefore create an earlier deadline unless an appropriate return extension is obtained. Filing an extension does not extend the 45-day identification period.

Your return due date depends on the taxpayer and circumstances. Do not simply enter April 15 for every entity. Ask your CPA to confirm the relevant due date, extension requirements and any separate tax-payment obligations. An extension to file is generally not an extension to pay.

Do weekends or holidays automatically give more time?

Do not plan on an ordinary weekend or holiday extension for these exchange periods. Treat the deadline as a hard limit until your advisers confirm a specific applicable rule. Arrange signatures, financing and transfers early enough to avoid relying on a last-day wire or a document delivered after business hours.

Disaster relief may apply to certain affected taxpayers and transactions, but it is not universal. A news headline or an old article about relief in a different year is not sufficient. Your adviser should check the actual IRS notice, location, covered dates and eligibility before applying any extension.

How should you coordinate the professionals?

Ask the qualified intermediary to provide the identification and completion dates in writing. Ask the CPA to confirm the return deadline and any extension. Ask the closing agent and offering representative to confirm the steps, funding dates and documents needed for the proposed replacement purchase. Assign a named person to each unfinished item.

A DST investment may be one potential replacement option, but an offering can fill, change or become unavailable. Identification does not guarantee that you can acquire an interest. Keep the investment decision separate from deadline pressure and review the offering's risks before committing.

When selecting the people involved, Winthco’s discussion of a Delaware statutory trust advisor provides context for the investment professional’s role.

What belongs in your exchange file?

Keep the sale closing statement, exchange agreement, signed identification notice, evidence of delivery, replacement closing documents and supporting calculations. Your tax adviser will need accurate records to determine the reporting, including Form 8824 where applicable.

Record why an option fits your objectives and how you evaluated risks. A completed exchange is not necessarily a suitable investment outcome. Preserving liquidity, understanding debt and avoiding excessive concentration remain important even when the tax mechanics are satisfied.

Keep the exchange file alongside the records needed for DST tax reporting, and ask your tax professional which documents apply to you.

What should you ask about each decision?

Your next-step checklist

1. Confirm the transfer date and exchange structure before closing.
2. Obtain written identification instructions from your qualified intermediary.
3. Confirm your taxpayer-specific return due date with your CPA.
4. Record both the identification date and earlier completion deadline.
5. Schedule funding and document delivery ahead of the final day.

Frequently asked questions

Sources and further reading

• IRS Form 8824 instructions
• Treasury deferred-exchange regulations
• IRS Publication 544

Sources checked October 2, 2026. This article explains general concepts; your facts and the applicable documents control.

Winthco DST services · Winthco evaluation overview · Editorial standards