Commencement Date Agreement

A commencement date agreement is a short signed document that confirms a commercial lease's actual commencement date, and usually its rent commencement and expiration dates, once they are known. It is used when the lease sets a floating start tied to possession or build-out, so the parties fix the real dates in writing. It controls the dates that the lease itself left open.

What Is a Commencement Date Agreement?

A commencement date agreement is a follow-on document, sometimes called a commencement letter or an acknowledgment of commencement date, that memorializes the exact date a lease term began once the triggering event has occurred. When a lease ties commencement to delivery of possession or substantial completion, the true date is not knowable at signing, and this agreement records it afterward.

The document is short and specific. It typically states the confirmed commencement date, the rent commencement date, the expiration date, and often the square footage as measured. According to Stratafolio, a lease commencement letter "provides formal confirmation of the lease start date," which gives both parties a single authoritative record instead of a date they must recompute from the lease's conditions.

For abstraction, the commencement date agreement is the controlling source for dates. When it exists, it overrides the estimated or conditional dates in the lease, because it states what actually happened. An abstract that pulls the commencement date from the lease's original estimate, while ignoring a later commencement date agreement, will carry the wrong term and the wrong expiration.

Why a Commencement Date Agreement Matters

A commencement date agreement matters because it converts a lease's floating, conditional start into a fixed date that governs the term. Leases often estimate the commencement date because it depends on when the landlord delivers the space, and the National Real Estate Investor notes tenants seek a floating date so rent does not begin before they are ready. This agreement is what pins the estimate to reality.

For anyone abstracting or underwriting, it is the tie-breaker. If the lease says the term begins on delivery and a commencement date agreement later confirms that day, the agreement, not the lease's estimate, sets the expiration and every critical date. The quotable point for an operator: when a commencement date agreement exists, it is the controlling document for the term, so a lease abstract that stops at the original lease will state dates that never came true.

Example

A lease signed January 15, 2026 estimates a commencement date of April 1, 2026 for a 7-year term, but ties actual commencement to delivery of possession. The landlord delivers on May 20, 2026, and a commencement date agreement confirms the real dates. The table compares the lease estimate to the confirmed agreement.

The lease's estimated expiration was March 31, 2033. The commencement date agreement moves actual commencement to May 20, 2026, so the 7-year term now expires May 19, 2033, 49 days later than the estimate. An abstract that used the lease's April 1 estimate would understate the remaining term by 49 days and set every renewal and option deadline against the wrong expiration.

Variations and Edge Cases

A commencement date agreement varies in what it confirms and how binding it is, so an abstractor should read it rather than assume it only carries a date. The table lists common variants and their treatment.

The common mistake is abstracting the lease and never checking whether a commencement date agreement was later signed. Because the agreement confirms dates the lease could only estimate, a complete abstract must reconcile the two and treat the agreement as controlling for the dates it fixes.

Commencement Date Agreement vs Lease Amendment

A commencement date agreement is often confused with a lease amendment, but they do different work. A commencement date agreement confirms dates the lease already left open, recording what actually happened without changing the deal. A lease amendment changes the agreed terms of the lease, such as rent, term length, or space, altering the bargain itself.

The distinction is confirmation versus change. A commencement date agreement fills in a blank the lease intentionally left, so it is not a renegotiation. A lease amendment modifies terms the parties had already fixed. An abstractor treats the commencement date agreement as the authority on the dates it confirms, and the amendment as the authority on the terms it changes, and must read both against the original lease.

Frequently Asked Questions

What does a commencement date agreement confirm?A commencement date agreement confirms the lease's actual commencement date, usually the rent commencement date and the expiration date, and sometimes the measured square footage. It is signed after the triggering event, such as delivery of possession, so the parties have one authoritative record of dates the lease could only estimate at signing.

Does a commencement date agreement override the lease?For the dates it confirms, a commencement date agreement generally controls over the lease's original estimate, because it records what actually happened. It does not change the deal terms; it fixes dates the lease left open. When abstracting, treat the agreement as the authority on the commencement, rent commencement, and expiration dates it states.

Is a commencement date agreement the same as a commencement letter?Yes, a commencement date agreement, a commencement letter, and an acknowledgment of commencement date describe the same instrument: a signed document that confirms a lease's start and related dates once known. The names vary by drafter, but the function is the same, and each should be captured in a lease abstract.

Related Terms

• Commercial Lease Agreement

• Lease Critical Dates

• Rent Commencement Date

• Lease Abstract

• Lease Amendment