Cost Segregation on a Related-Party Purchase
Practical decisions for business owners and real estate owners.
The decision
A related-party property purchase can still require an asset classification analysis, but a cost segregation report does not establish eligibility for bonus depreciation. Review the seller relationship and the buyer’s basis before applying an accelerated deduction to the report.
Published · AE Tax Advisors Team
Why the seller matters before the engineer starts
A business owner may buy a warehouse from a family member, purchase a building held by another company in the ownership group, or move property between entities. Each can look like a new acquisition in the bookkeeping system. The tax result depends on the legal transaction, ownership attribution, consideration, and basis rules. A new closing statement or LLC name is not enough to establish a qualifying purchase.
The used-property bonus rules include restrictions involving prior use by the taxpayer, related parties, and certain carryover-basis acquisitions. The related-party analysis refers to statutory relationships, including attribution; it is broader than asking whether two companies have identical names. A study can identify shorter-lived assets while the acquisition still fails a bonus requirement. See the IRS regulations linked below for the underlying framework.
Build a transaction map
Prepare a one-page diagram showing the seller, purchaser, entity tax classifications, owners, and ownership percentages immediately before and after closing. List family relationships separately. Include trusts, partnerships, and corporations rather than stopping at the person signing the deed. Ask the tax preparer to identify whether the transaction is a taxable asset purchase, contribution, distribution, interest purchase, or transfer disregarded for federal tax purposes.
Next, reconcile the cash paid, debt assumed, and consideration allocated to land, building, and separately purchased assets. Retain the agreement and supporting valuation. A purchase of an interest in a property-owning partnership is a different analysis from a purchase of the property itself; do not automatically apply the buyer’s interest price to a new building depreciation schedule.
Illustrative planning comparison
Assume an owner budgets $1.4 million for a building transaction and a preliminary study identifies $180,000 of components for shorter recovery periods. One projection treats the entire $180,000 as immediately deductible. A second projection flags the seller relationship and leaves bonus eligibility unresolved. Both projections use the same engineering estimate, but only the second identifies the missing tax decision. The owner should not reduce an estimated payment based on the first projection until the acquisition requirements and loss limitations are resolved.
This is a hypothetical review problem, not a promised deduction. If bonus is unavailable, the classification work may still affect regular depreciation. Model that alternative with the correct methods and conventions instead of treating the study as either a complete write-off or worthless.
Questions to resolve before signing a study proposal
- Who is the seller for federal tax purposes, including disregarded entities?
- Does an ownership or family relationship trigger a restriction?
- Was the property previously used by this taxpayer?
- Is the new basis a purchase basis, carryover basis, or partner-specific adjustment?
- Which assets and tax years are included in the engagement?
- Who will confirm bonus eligibility and implement the depreciation schedule?
Keep two conclusions separate
Ask for an asset-classification conclusion and a tax-eligibility conclusion. The former should explain the components and costs; the latter should address the acquisition and taxpayer facts. Save both with the return workpapers. If the related-party question is still open, label the cash-flow model accordingly and avoid presenting a provisional estimate as spendable tax savings.
For the general study workflow, use cost segregation services. For an existing report, use the report reconciliation checklist. These address different decisions from the seller-relationship review.
Source and scope
IRS final bonus depreciation regulations, used-property acquisition requirements. Source checked September 26, 2026. Examples are hypothetical. This guide is general education, not a conclusion about your return. Read our editorial policy.
Related Reading
Talk Through Your Situation
Every situation turns on its own facts. Schedule a discovery call and we will walk through what applies to you, what it is worth, and what it would take to put it in place.