argue that the contract should be void. The deal created a

In commercial practice the term "debenture" typically refers to the document that evidences a secured debt, although in law the definition may also cover unsecured debts (like any "IOU").[46] The legal definition is relevant for certain tax statutes, so for instance in British India Steam Navigation Co v IRC[47] Lindley J held that a simple "acknowledgement of indebtedness" was a debenture, which meant that a paper on which directors promised to pay the holder £100 in 1882 and 5% interest each half year was enough, and as a result subject to pay duty under the Stamp Act 1870. The definition depends on the purpose of the statutory provision for which it is used. It matters because debenture holders have the right to company accounts and the director's report,[48] because debenture holders must be recorded on a company register which other debenture holders may inspect,[49] and when issued by a company, debentures are not subject to the rule against "clogs on the equity of redemption". This old equitable rule was a form of common law consumer protection, which held that if a person contracted for a mortgage, they must always have the right to pay off the debt and get full title to their property back. The mortgage agreement could not be turned into a sale to the lender,[50] and one could not contract for a perpetual period for interest repayments. However, because the rule limited on contractual freedom to protect borrowers with weaker bargaining power, it was thought to be inappropriate for companies. In Kreglinger v New Patagonia Meat and Cold Storage Co Ltd[51] the House of Lords held that an agreement by New Patagonia to sell sheepskins exclusively to Kreglinger in return for a £10,000 loan secured by a floating charge would persist for five years even after the principal sum was repaid. The contract to keep buying exclusively was construed to not be a clog on redeeming autonomy from the loan because the rule's purpose was to preclude unconscionable bargains. Subsequently, the clog on the equity of redemption rule as a whole was abolished by what is now section 739 of the Companies Act 2006. In Knightsbridge Estates Trust Ltd v Byrne[52] the House of Lords applied this so that when Knightsbridge took a secured loan of £310,000 from Mr Byrne and contracted to repay interest over 40 years, Knightsbridge could not then argue that the contract should be void. The deal created a debenture under the Act, and so this rule of equity was not applied.
Registration
See also: Companies House
In London the main office of Companies House, where all charges against a company need to be registered, is on Bloomsbury Street, just near the British Museum.