We just won a case that every commercial property buyer should study. Our client purchased a shopping plaza. Years earlier, the seller had signed a broker agreement that promised an additional commission if a tenant later renewed the lease. After our client closed, the tenant renewed—and the broker showed up demanding payment from the new owner.

Here’s the key: buying real estate does not automatically make you responsible for the seller’s side agreements. Unless the buyer expressly assumes a liability—or it truly “runs with the land”—that obligation stays with the seller. That’s why we won.

Why Buyers Think They’re Stuck (But Often Aren’t)

• The broker points to the tenant’s renewal and says “commission earned.”
• The lease mentions brokers “in general” but doesn’t bind future owners to a separate commission agreement.
• The purchase documents are silent on broker liabilities.

In NY/NJ, contractual liabilities remain personal to the party who undertook them unless expressly assumed by the buyer. Broker commission agreements are typically separate contracts with the seller—not covenants that run with the land.

The Controlling Rule in Plain English

Asset transfers don’t transfer personal liabilities by default. A buyer takes title to the real estate and the assigned leases, but not to the seller’s separate promises (like a future broker commission) unless the buyer expressly agrees to assume them in the purchase and sale agreement (or in a clear assignment and assumption of liabilities).

Where Deals Go Sideways

• Vague lease language: Generic references to “brokers” are treated like disclosures, not binding promises by future owners.
• Hidden side letters: A seller signs a broker side letter for future renewals and never discloses it.
• “By operation of law” myths: The notion that “ownership changed, so you owe” is wrong for personal obligations.
• Sloppy assignments: Overbroad language in assignment/assumption documents that inadvertently adopts liabilities.

How Buyers Protect Themselves (Pre-Closing Checklist)

1. Demand written broker disclosures: Ask for all listing, commission, and side agreements—past and future.
2. Use a clean assumption schedule: Your APA/PSA should list exactly which liabilities you do assume (and disclaim all others).
3. Get estoppel certificates right: Tenant and broker estoppels should confirm no unpaid commissions are owed by landlord—and that any future commissions remain seller’s obligation unless expressly assumed.
4. Align the lease assignment: The landlord’s assignment should transfer leases, not seller’s separate brokerage obligations.
5. Protect with indemnities and escrows: If something is uncertain, use a targeted escrow or seller indemnity for broker claims.

What If a Broker Demands Payment After Closing?

• Request the contract: Ask for the actual brokerage agreement and any side letters.
• Check your PSA/assignment: Confirm you never assumed the obligation.
• Map the parties: If the agreement is between broker and prior owner, that’s your first defense.
• Review the lease: If the lease is silent on future commissions from the landlord, your position strengthens.
• Respond in writing: Reserve rights; point to non-assumption; request withdrawal. If necessary, seek a declaratory judgment.

When Buyers Do Become Liable

There are narrow situations where a buyer can be on the hook:

• You expressly assume the commission obligation in the PSA or assignment.
• The lease itself contains a clear, running covenant obligating any “landlord” (including successors) to pay a defined commission on renewals.
• You accept a purchase credit in lieu of seller paying the commission, effectively stepping into the obligation.

Bottom Line

Most post-closing broker-commission claims fail against the buyer because the obligation doesn’t run with the land and wasn’t expressly assumed. The right response is a calm, documented “no”—backed by your PSA, assignment, and the absence of any assumption language.

This article provides general information for NY/NJ commercial property owners and is not legal advice. Outcomes depend on contract language and transaction documents.