The short answer
Assigning a commercial lease transfers the tenant’s interest to a new tenant. Subletting keeps the original tenant in place. Either way, the original tenant usually remains liable to the landlord unless the landlord signs a release.
Where it fits in your case
It usually comes up when a business sells, relocates, or downsizes, and again if the new tenant defaults.
What to expect
Landlord consent is commonly required. Leases may say consent cannot be unreasonably withheld, or may give the landlord broad discretion.
Continuing liability. Without a written release or novation, the original tenant can be pursued for the new tenant’s unpaid rent.
Personal guarantees may also survive the assignment.
Business sales often include an assignment of the lease that should be worked out with the landlord before closing.
What we need from you
The lease and amendments, any guaranty, the assignment or sublease documents, and the landlord’s consent.
Common misconceptions
“We assigned the lease, so we’re off the hook.” Not without a release.
“The landlord can’t refuse.” That depends on the consent clause.