Also known as an estoppel certificate. In a real estate context, a tenant certifies on certain material terms of its lease as of a particular date. Typically an estoppel certificate is delivered by a tenant to a landlord who is either financing or selling the building where the tenant is located.

Once the tenant certifies to certain matters in the estoppel certificate, the tenant cannot make a claim contrary to the matters certified to in the estoppel certificate.

An estoppel certificate includes a certification of material lease matters, such as the:

An estoppel certificate can also be delivered by a landlord to a tenant, certifying to the same material lease terms. However, it is less common for the landlord to be obligated to deliver an estoppel certificate to the tenant under the terms of the lease.