company has not the restraint which the fear of bankruptcy

While both need to be registered, the distinction between a fixed and a floating charge matters greatly because floating charges are subordinated by the Insolvency Act 1986 to insolvency practitioners' expenses under section 176ZA,[59] preferential creditors (employees' wages up to £800 per person, pension contributions and the EU coal and steel levies) under section 175 and Schedule 6 and unsecured creditors' claims up to a maximum of £600,000 under section 176A. The floating charge was invented as a form of security in the late nineteenth century, as a concept which would apply to the whole of the assets of an undertaking. The leading company law case, Salomon v A Salomon & Co Ltd,[10] exemplified that a floating charge holder (even if it was the director and almost sole shareholder of the company) could enforce their priority ahead of all other persons. As Lord MacNaghten said, "Everybody knows that when there is a winding-up debenture-holders generally step in and sweep off everything; and a great scandal it is." Parliament responded with the Preferential Payments in Bankruptcy Amendment Act 1897, which created a new category of preferential creditors - at the time, employees and the tax authorities - who would be able to collect their debts after fixed charge holders, but before floating charge holders. In interpreting the scope of a floating charge the leading case was Re Yorkshire Woolcombers Association Ltd[60] where a receiver contended an instrument was void because it had not been registered. Romer LJ agreed, and held that the hallmarks of a floating charge were that (1) assets were charged present and future and (2) change in the ordinary course of business, and most importantly (3) until a step is taken by the charge holder "the company may carry on its business in the ordinary way".[61] A floating charge is not, technically speaking, a true security until a date of its "crystallisation", when it metaphorically descends and "fixes" onto the assets in a business' possession at that time.

Businesses, and the banks who had previously enjoyed uncompromised priority for their security, increasingly looked for ways to circumvent the effect of the insolvency legislation's scheme of priorities. A floating charge, in order for its value to be ascertained, must have "crystallised" into a fixed charge on some particular date, usually set by agreement.[62] Before the date of crystallisation (given the charge merely "floats" over no particular property) there is the possibility that a company could both charge out property to creditors with priority,[63] or that other creditors could set-off claims against property subject to the (uncrystallised) floating charge.[64] Furthermore, other security interests (such as a contractual lien) will take priority to a crystallised floating charge if it arises before in time.[65] But after crystallisation, assets received by the company can be caught by the charge.[66] One way for companies to gain priority with floating charges originally was to stipulate in the charge agreement that the charge would convert from "floating" to "fixed" automatically on some event before the date of insolvency. According to the default rules at common law, floating charges impliedly crystallise when a receiver is appointed, if a business ceases or is sold, if a company is would up, or if under the terms of the debenture provision is made for crystallisation on reasonable notice from the charge holder.[67] However an automatic crystallisation clause would mean that at the time of insolvency - when preferential creditors' claims are determined - there would be no floating charge above which preferential creditors could be elevated. The courts held that it was legitimate for security agreements to have this effect. In Re Brightlife Ltd[68] Brightlife Ltd had contracted with its bank, Norandex, to allow a floating charge to be converted to a fixed charge on notice, and this was done one week before a voluntary winding up resolution. Against the argument that public policy should restrict the events allowing for crystallisation, Hoffmann J held that in his view it was not "open to the courts to restrict the contractual freedom of parties to a floating charge on such grounds." Parliament, however, intervened to state in the Insolvency Act 1986 section 251 that if a charge was created as a floating charge, it would deem to remain a floating charge at the point of insolvency, regardless of whether it had crystallised.

‘A company has not the restraint which the fear of bankruptcy imposes on an individual trader... [For] directors of a company... little or no personal discredit falls upon them if their company fails to pay a dividend to its trade creditors. It is, therefore, all the more important that the amount and manner of borrowing by a corporation should be upon a satisfactory basis... We do not consider that a company should have any greater facility for borrowing than an individual, and we think that while a company should have unrestricted power to mortgage or charge its fixed assets and should be allowed to contract that other fixed assets substituted for those charged should become subject to the charge, and the company should also be capable of charging existing chattels and book debts or other things in action, it ought to be rendered incapable of charging after acquired chattels, or future book debts, or other property not in existence at the time of the creation of the charge.’
Minority of the Loreburn Committee, Report of the Company Law Amendment Committee (1906) Cd 3052, 28

these do not require registration

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.

While all records of all a company's debentures need to be kept by the company, debentures secured by a "charge" must additionally be registered under the Companies Act 2006 section 860 with Companies House,[53] along with any charge on land, negotiable instruments, uncalled shares, book debts and floating charges, among other things. The purpose of registration is chiefly to publicise which creditors take priority, so that creditors can assess a company's risk profile when making lending decisions. The sanction for failure to register is that the charge becomes void, and unenforceable. This does not extinguish the debt itself, but any advantage from priority is lost and the lender will be an unsecured creditor. In National Provincial Bank v Charnley[54] there had been a dispute about which creditor should have priority after Mr Charnley's assets had been seized, with the Bank claiming its charge was first and properly registered. Giving judgment for the bank Atkin LJ held that a charge, which will confer priority, simply arises through a contract, "where in a transaction for value both parties evince an intention that property, existing or future, shall be made available as security for the payment of a debt, and that the creditor shall have a present right to have it made available, there is a charge". This means a charge simply arises by virtue of contractual freedom. Legal and equitable charges are two of four kinds of security created through consent recognised in English law.[55] A legal charge, more usually called a mortgage, is a transfer of legal title to property on condition that when a debt is repaid title will be reconveyed.[56] An equitable charge used to be distinct in that it would not be protected against bona fide purchasers without notice of the interest, but now registration has removed this distinction. In addition the law recognises a pledge, where a person hands over some property in return for a loan,[57] and a possessory lien, where a lender retains property already in their possession for some other reason until a debt is discharged,[58] but these do not require registration.
Fixed and floating charges
Main articles: Fixed charge and Floating charge

people, should the property be wrongfully disposed of. Third,

See also: Netting and Set-off (law)
Secured lending
Main articles: UK banking law, Banking law, and Security interest
The Bank of England (est 1694) is the lender to all other banks, at an interest rate set by the Monetary Policy Committee under the Bank of England Act 1998. When lending on money to businesses at a higher interest rate, banks will contract for fixed and floating charges to decrease their risk and stabilise profits.

While UK insolvency law fixes a priority regime, and within each class of creditor distribution of assets is proportional or pari passu, creditors can "jump up" the priority ladder through contracts. A contract for a security interest, which is traditionally conceptualised as creating a proprietary right that is enforceable against third parties, will generally allow the secured creditor to take assets away, free from competing claims of other creditors if the company cannot service its debts. This is the first and foremost function of a security interest: to elevate the creditor's place in the insolvency queue. A second function of security is to allow the creditor to trace the value in an asset through different people, should the property be wrongfully disposed of. Third, security assists independent, out-of-court enforcement for debt repayment (subject to the statutory moratorium on insolvency), and so provides a lever against which the secured lender can push for control's over the company's management.[41] However, given the adverse distributional impact between creditors, the economic effect of secured lending is frequently characterised as a negative externality.[42] With an ostensibly private contract between a secured lender and a company, assets that would be available to other creditors are diminished without their consent and without them being privy to the bargain. Nevertheless, security interests are commonly argued to facilitate the raising of capital and hence economic development, which is argued to indirectly benefits all creditors.[43] UK law has, so far, struck a compromise approach of enforcing all "fixed" or "specific" security interests, but only partially enforcing floating charges that cover a range of assets that a company trades with. The holders of a floating charge take subject to preferential creditors and a "ring fenced fund" for up to a maximum of £600,000 reserved for paying unsecured creditors.[44] The law requires that details of most kinds of security interests are filed on the register of charges kept by Companies House. However this does not include transactions with the same effect of elevating creditors in the priority queue, such as a retention of title clause or a Quistclose trust.[45]
Debentures
Main article: Debenture