What it means
When a mortgaged commercial property is sold or foreclosed, the tenant's world shifts underfoot. Attornment is the tenant's promise to accept the new owner, whether a buyer or a foreclosing lender, as the landlord under the existing lease.
The lease continues, but the tenant formally acknowledges the new party on the other side of it. Attornment rarely travels alone.
It is one leg of the standard SNDA triad: subordination, non-disturbance, and attornment, a modern standardised form of an old property law idea in which a tenant's acknowledgment of a lord or new owner defined the tenancy itself. The tenant subordinates the lease to the lender's mortgage, the lender promises not to disturb the tenancy if it forecloses, and the tenant attorns to whoever ends up owning the building.
Federal lease clauses, such as the GSA's standard subordination, nondisturbance and attornment provision in the acquisition regulations, show the trio operating in government leasing. The exchange is a bargain of protections.
The lender gets certainty that the lease survives the mortgage and the tenant will keep paying after foreclosure, while the tenant gets certainty that foreclosure will not evict it. Attornment is the tenant's half of the promise, and it only makes sense paired with the non-disturbance half from the lender.
Without it, foreclosure can create genuine chaos. In some jurisdictions a foreclosure can wipe out leases junior to the mortgage, leaving an operating business suddenly negotiating with a lender that never wanted to be a landlord.
The SNDA exists precisely to take that scenario off the table for all three parties. Practical details still matter: the tenant should confirm the new owner's identity before redirecting rent, insist on the non-disturbance commitment in writing, and keep records of every attornment letter signed.
Paying rent to the wrong party after a quiet ownership change is a real and expensive mistake. For managers occupying leased space, attornment letters arrive at unsettling moments, usually when the landlord is in financial trouble.
Signing without reading the companion non-disturbance terms can leave the business committed to a new owner with none of the protections the original lease negotiated. Lenders review these provisions at underwriting, since a rent roll whose leases all include enforceable SNDA packages is worth more as collateral, and tenants in strong positions sometimes secure automatic attornment language in exchange for stronger non-disturbance promises.
In practice
Real-world examples.
Example
A tenant signs an attornment letter recognising the foreclosing lender as its new landlord. The letter confirms that the lease terms, including rent and expiry date, continue unchanged. The tenant then updates its payment instructions only after the lender confirms the new bank account in writing.
Example
An SNDA package subordinates the lease, guarantees non-disturbance, and records the tenant's attornment. The tenant negotiates it when signing a ten-year lease, before any lender is in trouble. The lender in turn treats the lease as secure income when valuing the building as collateral.
Example
A business nearly pays rent to the former owner before its attornment letter identifies the correct new landlord. The finance clerk spots the change of payee when comparing the letter with the usual instructions and holds the payment. A phone call to the new owner's agent confirms the details, and the rent is paid correctly.
Formula
Calculation
There is no formula for attornment itself, but the cost of getting the paperwork wrong can be measured. Rent at risk = monthly rent x months paid to the wrong party. Example: a tenant paying $12,000 a month that keeps paying the former owner for three months after a foreclosure has $12,000 x 3 = $36,000 at risk, because the new owner may still demand that rent again.
The protective test is structural: attornment is safe for the tenant only when paired with the lender's written non-disturbance commitment, forming the full SNDA package.Case study
Seen in the real world.
This is a fictional example. Calla & Rowe, a fictional retailer, receives an attornment request after its landlord's lender forecloses on the building. Because the lease included an SNDA, Calla & Rowe attorns to the lender, rent redirects smoothly, and its lease terms survive intact.
A neighbouring tenant without the agreement spends months renegotiating from scratch. Afterwards Calla & Rowe adds SNDA review to its checklist for every new store lease. Its property manager asks the landlord for the lender's standard form during negotiations, not after signing, and keeps signed copies in the lease file.
Watch out
Common mistakes.
- Signing attornment without the non-disturbance commitment, committing to a new owner while gaining no protection in return. The halves are exchanged, not optional.
- Redirecting rent on a phone call alone, without written confirmation of who legally owns the property. Written notice is the safe trigger.
- Ignoring SNDA negotiations at lease signing, leaving the tenancy exposed if the landlord's lender later forecloses. Lease review belongs at signing.
Questions
People also ask.
What does it mean to attorn?
The tenant formally accepts a new owner of the property as the landlord and agrees to perform the lease in their favour. The lease then runs with the new owner.
What is an SNDA?
Subordination, non-disturbance, and attornment: the lease ranks below the mortgage, the lender preserves the tenancy, and the tenant accepts the new owner. Each element protects a different party.
Can foreclosure cancel a lease?
In some cases yes, if the lease is junior to the foreclosed mortgage, which is why tenants negotiate non-disturbance protection in advance. The SNDA is negotiated before trouble starts.
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