A finance lawyer is most likely to associate the term with a document that is executed in favour of a creditor with a covenant to pay the creditor and which grants security over the whole or substantially the whole of a company's assets. Typically a debenture creates a fixed charge over the assets of the company which are not disposed of in the ordinary course of business and a floating charge over the rest of the company's undertaking. It grants the creditor rights as mortgagee or chargee such as the authority to appoint an administrator or administrative receiver with wide powers to run the company's business and realise its assets.

In a corporate context, the Companies Act 2006 provides a broader interpretation of debenture and defines it as including "debenture stock, bonds and any other securities of a company, whether constituting a charge on the assets of the company or not" (section 738). In this context, a debenture is not a "security document" but rather an instrument acknowledging corporate indebtedness.