A consent-for-modification clause will stretch only so far.

When tenants go out of business landlords pay the price. One way to cushion the financial blow is to go after the tenant’s parent corporation for the unpaid rents and other revenues owed under the lease. But without an express lease guaranty, holding a corporation liable for the debts of its subsidiaries is a tough thing to pull off. Recognition of corporations as distinct legal entities that are separate from their subsidiaries and affiliates is a fundamental and longstanding principle of U.S. law. By the same token, insulation from liability is far from absolute.