Introduction
OP units let a REIT buy real estate with a currency cash cannot match: tax deferral. A property owner who would owe a large capital-gains bill on a sale can instead contribute the asset to a REIT's operating partnership under Section 721 and take partnership units, deferring the tax indefinitely. That advantage makes units a genuine acquisition currency, capable of winning a deal against a higher all-cash bid. But the moment a seller takes units, the transaction grows a long tail. The REIT typically promises not to sell the contributed property or pay down its debt for years, obligations that bind the buyer well after closing and that a deal team has to price into the bargain.
Why a Seller Takes Units Instead of Cash
The seller most drawn to OP units is one sitting on a low tax basis. After decades of depreciation, a long-held property often carries a basis far below its market value, so an outright sale would trigger a punishing capital-gains and depreciation-recapture bill. Contributing the property for units defers that entire liability: under Section 721, no gain is recognized at contribution, and the seller's carryover basis moves into the units. The deferred gain stays parked until the units are converted to REIT shares or the partnership sells the asset, the carryover and conversion mechanics detailed in OP units and 721 exchanges.
- Section 721 exchange
The contribution of real property to a REIT's operating partnership in return for partnership units, without recognizing taxable gain at the time of the contribution. It is the UPREIT counterpart to a 1031 exchange, but the owner ends up holding partnership units rather than replacement real estate.
The deferral becomes permanent in the right hands. An owner who holds the units until death passes them to heirs at a stepped-up basis, which can erase the deferred gain entirely, turning a tax deferral into a tax elimination. That estate-planning payoff is why family owners and long-tenured sponsors will often accept units even when a cash buyer offers more on paper.
| Dimension | All-cash sale | OP unit contribution |
|---|---|---|
| Capital-gains tax | Due at closing | Deferred under Section 721 |
| Liquidity | Immediate | Locked until conversion or redemption |
| Ongoing exposure | None | REIT distributions and unit price |
| Estate outcome | Gain sits in the estate | Step-up at death can erase the gain |
The Tax Protection Agreement
The price of that deferral, from the buyer's side, is the tax protection agreement, the document that turns a one-time contribution into a multi-year obligation. Because the seller's gain is only deferred, anything the REIT later does that triggers the gain, chiefly selling the contributed property, would blow up the very benefit the seller bargained for. The TPA constrains the REIT from doing so and compensates the seller if it does, and it sits alongside the registration and pricing terms covered in OP units as acquisition currency in REIT capital markets.
- Tax protection agreement (TPA)
A contract between a REIT and a contributing partner that protects the partner's deferred tax position, typically by restricting the REIT from selling the contributed property for a set period and by maintaining enough partnership debt allocated to the partner to prevent a taxable event. If the REIT breaches, it owes a make-whole payment covering the partner's resulting tax.
The taxable-sale restriction
The first promise is a taxable-sale restriction. The REIT agrees not to sell or otherwise trigger gain on the contributed property for a defined period, commonly five to seven years, and owes a make-whole payment grossing up the seller's tax if it breaches. The covenant is what gives the deferral its teeth: without it, the REIT could contribute the asset and then flip it, handing the seller the very tax bill they took units to avoid.
Debt maintenance and phantom income
The second promise is debt maintenance, and it is the subtler one. Contributing partners with low-basis property often carry negative tax capital accounts, and they need a minimum allocation of partnership debt to avoid recognizing phantom income, taxable gain with no cash behind it to pay the bill. The REIT therefore commits to keep a specified level of debt outstanding and allocable to those partners, and to apply a Section 704(c) method governing how the built-in gain and depreciation are shared. A real example sits in public filings: Phillips Edison and Company's tax protection agreements spell out exactly these taxable-sale and debt-maintenance protections for the partners who contributed shopping centers into its operating partnership.
What It Costs the Buyer
The reason a deal team cannot treat units as free money is that the TPA strips the REIT of flexibility it would otherwise have. A property bought for cash can be sold, refinanced, or unencumbered whenever strategy dictates. A property contributed for units, by contrast, is effectively frozen: the REIT cannot sell it during the protection period without owing a make-whole, and cannot deleverage it because cutting the debt would expose contributors to phantom income and trigger compensation. The currency is cheap at closing but carries a multi-year liability that constrains portfolio management.
That cost has to be weighed against the price advantage units provide. In practice the constraints are most palatable for long-term hold assets the REIT intends to keep anyway, where a multi-year no-sale covenant changes nothing it planned to do. They are least palatable for assets the REIT might want to recycle, which is why a buyer will often pay cash for a property it sees as a trade and reserve units for the core holdings it means to keep. The trade-off mirrors the broader stock, cash, and mixed consideration decision, just applied at the asset level rather than the corporate level.
When OP Units Win the Deal
Units come into their own in fragmented, founder-owned markets where roll-ups are the strategy. A REIT assembling a portfolio out of dozens of family-owned properties can offer each seller tax-deferred units, often the only structure that lets a long-time owner monetize without a crippling tax bill, and thereby consolidate assets that a pure cash buyer could never pry loose at a sensible price. The currency is decisive precisely where the sellers are tax-sensitive and the assets are core to the acquirer.
The competitive logic is simple once the tax math is clear. Against a cash bidder, a REIT offering units does not need to match the gross price; it needs to beat the seller's after-tax proceeds, and the deferral can make a lower unit offer worth more than a higher cash one. That is why UPREIT contributions remain a live tool throughout a REIT's life rather than a one-time formation event, and why they connect directly to the broader architecture of real estate M&A: the choice of currency, here units versus cash, is again the lever that decides who can win an asset and at what real cost.


