Top Lease
A new oil and gas lease signed on a tract that is already leased, taking effect only if and when the existing lease expires or terminates.
A top lease is an oil and gas lease granted on a tract that is already burdened by an existing (the "bottom" or base) lease. The top lease is written to become effective only if and when the prior lease expires, terminates, or is released — so a company can lock up future rights to acreage it expects to come open without waiting for the current lease to lapse.
Operators top-lease when they believe an existing lease is near the end of its primary term or is not truly held by production, and they want to secure the tract before a competitor does. The top-lease bonus is often lower than a clean lease because the lessee is buying a contingent, not immediate, right.
For a mineral owner, a top lease can be a useful way to capture a second bonus on acreage you think will free up. But signing one while a valid lease is still in force can trigger disputes — and some leases or state rules limit them — so confirm the status of the existing lease and have the top-lease language reviewed. This is general information, not legal advice.