It is pretty common knowledge that your broker helps to put all the appropriate documentation together such as the Lease, Work letter, and certainly the offers leading up to the Lease.
But what about after the Lease is signed. Assuming you continue to engage your broker AFTER the Lease is signed, one important document you may find you are required to sign is the Commencement Date Amendment. This is a document which is usually part of the Lease but purposely left blank. After you occupy the Premises, all the blanks are filled in including the actual size of the space and, most important, the actual start and termination date.
Often, leases state a projected start date but do to completion of TI's or other delays, the lease may actually start later. It is vital this document be signed by both parties. We can't tell you how many times we get close to termination with a new clients only to find no one is sure when that termination actually takes place-landlords change-property managers change-even tenant's management changes. After all is said and done, all you have is the four corners of some document.
Have your broker make sure this is executed if you start any day but the date stated on the Lease.