Form 8824 Mistakes and Audit Triggers
9 min read · Planning & Execution · Last updated
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Key Takeaways
Form 8824 must be filed with your tax return when you do a 1031 exchange. Common mistakes include incorrect basis calculations, wrong date entries, missing related party reporting, and boot calculation errors. Large exchanges with no recognized gain often trigger audits because the IRS wants to verify the exchange actually occurred and qualifies.
Form 8824, "Like-Kind Exchanges," must be filed with your federal tax return for the year the exchange closed. Even if no gain is recognized (full deferral), the form is required. Mistakes on Form 8824 can trigger audits, produce incorrect tax calculations, and in some cases jeopardize the deferral itself.
Here are the most common errors, why they matter, and how to avoid them.
Mistake 1: Incorrect basis calculation
How it happens. The investor uses the purchase price of the replacement property as their new basis instead of calculating it from the relinquished property's adjusted basis. Or they forget to subtract accumulated depreciation from the relinquished property's cost basis.
Why it matters. Basis determines your depreciation schedule and your future capital gains calculation. An inflated basis means you underpay tax now and create a problem in a future audit or sale. An understated basis means you may overpay.
How to avoid it. The replacement property basis formula is:
Adjusted basis of relinquished property + boot paid - boot received + gain recognized
Work with a CPA who has handled 1031 exchanges. They will reconcile the basis calculation with your depreciation schedule and closing documents.
Mistake 2: Wrong dates
How it happens. Investors confuse the listing date, offer acceptance date, or contract date with the actual closing date. Day 1 of the exchange is the date you transfer title (the date on the closing statement), not the date you signed the agreement.
Why it matters. The IRS compares Form 8824 dates to closing documents. Mismatches trigger questions and can lead to a determination that you missed a deadline.
How to avoid it. Pull dates directly from closing statements for both the relinquished and replacement properties. Confirm with your QI.
Mistake 3: Not filing Form 8824 at all
How it happens. The investor deferred the entire gain and assumes no form is needed because no tax is owed.
Why it matters. Form 8824 is required regardless of whether gain is recognized. It establishes the basis for the replacement property and documents the exchange for IRS records. Failure to file can result in penalties, and if the IRS discovers the omission, it may treat the transaction as a taxable sale.
How to avoid it. File Form 8824 with your return in every year you complete an exchange. Your CPA should include it as a matter of course.
Mistake 4: Omitting related-party disclosure
How it happens. The investor does not realize the transaction involves a related party, or skips Part II of Form 8824 because it seems optional.
Why it matters. Part II requires disclosure of any related-party relationship (under IRC 267(b)). Omitting it when it applies looks like concealment. If the IRS discovers the relationship through other records, you have created an audit problem.
How to avoid it. Review the related-party definition before filing. If any party to the exchange is a spouse, sibling, parent, child, or entity you control (more than 50%), complete Part II.
Mistake 5: Boot calculation errors
How it happens. Boot is not always obvious. Cash boot is straightforward, but mortgage boot (debt relief without equivalent replacement debt) and hidden boot (prorations, personal property received at closing, non-qualifying closing costs) are easy to miss.
Why it matters. Understating boot means understating recognized gain, which means underpaying tax. Overstating boot means overpaying.
How to avoid it. Calculate boot as: cash received + non-like-kind property received + net debt relief - boot paid. Reconcile against both closing statements. Have your CPA review for hidden boot sources.
Mistake 6: Multi-property tracking errors
How it happens. Exchanges involving multiple relinquished or replacement properties require tracking each property separately. Values, basis allocations, and dates must match across all properties. Investors mix up which relinquished property corresponds to which replacement.
Why it matters. Incorrect allocation produces wrong basis figures for each replacement property, which affects depreciation and future gain calculations.
How to avoid it. List each property separately on Form 8824 (or on multiple copies of the form). Reconcile values with closing statements. Have your CPA organize the data before filing.
Audit triggers on Form 8824
Several characteristics attract IRS attention:
- Large exchanges with zero recognized gain
- Inconsistencies between Form 8824 and Schedules D or E
- Missing Form 8824 entirely
- Omitted related-party disclosure
- Short holding periods on replacement property
- Mismatched dates (Form 8824 vs. closing documents)
- Large boot with unclear documentation
Pre-filing checklist
Before your CPA files Form 8824:
- Dates match closing statements for both properties
- Adjusted basis of relinquished property accounts for accumulated depreciation
- Boot calculation is complete (cash, mortgage, and hidden boot)
- Replacement property basis follows the formula
- Related-party disclosure is completed if applicable
- All property descriptions are accurate and unambiguous
- Values reconcile with closing statements and QI records
The bottom line
Form 8824 is straightforward if you prepare the inputs correctly. The most expensive mistakes are basis errors (which compound over time) and omissions (which create audit triggers). Work with a CPA experienced in 1031 exchanges. The fee is modest compared to the cost of a basis error that surfaces years later or an audit triggered by a missing form.
Calculate your potential tax savings to understand what is at stake, and ensure your Form 8824 protects the deferral you worked to achieve.
The Bottom Line
Accurate Form 8824 preparation requires attention to detail and thorough documentation. Work with a CPA experienced in 1031 exchanges to minimize errors and audit risk.
Frequently Asked Questions
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