A break clause is a lease provision that lets the tenant, the landlord or both end the lease early at defined dates, subject to notice periods and conditions. For tenants it is the main escape valve on a long lease, and break dates drive real estate decision timetables.
Exercising a break is a data decision: you need to know, well before the notice deadline, whether the space is worth keeping. That is why utilisation reporting tends to get serious 12 to 18 months before a break date.