Letters patent (plural form for singular and plural) are a type oflegal instrument in the form of a published written order issued by amonarch,president or other head of state, generally granting an office, right,monopoly, title or status to a person orcorporation. Letters patent can be used for the creation ofcorporations, government offices, to grant city status orcoats of arms. Letters patent are issued for the appointment of representatives ofthe Crown, such asgovernors andgovernors-general ofCommonwealth realms, as well as appointing aRoyal Commission. In theUnited Kingdom, they are also issued for the creation ofpeers of the realm.

A particular form of letters patent has evolved into the modernintellectual property patent (referred to as a utilitypatent ordesign patent inUnited States patent law) granting exclusive rights in aninvention or design. In this case, it is essential that the written grant should be in the form of a public document so other inventors can consult it both to avoid infringement (while the patent remains in force) and to understand how to put it into practical use (once the patent rights expire). In theHoly Roman Empire,Austrian Empire, andAustria-Hungary, imperial patent was also the highest form of generally binding legal regulations, e.g.Patent of Toleration,Serfdom Patent, etc.

The opposite of letters patent areletters close (Latin:litterae clausae), which are personal in nature and sealed so that only the recipient can read their contents. Letters patent are thus comparable to other kinds ofopen letter in that their audience is wide. It is not clear how the contents of letters patent became widely published before collection by the addressee, for example whether they were left after sealing by the king for inspection during a certain period by courtiers in a royal palace, who would disseminate the contents back to the gentry in the shires through normal conversation and social intercourse. Today, for example, it is a convention for the British prime minister to announce that they have left a document they wish to enter the public domain "in thelibrary of theHouse of Commons", where it may be freely perused by all members ofparliament.

Letters patent are so named from the Latin verbpatī,patior, to lie open, exposed, accessible.^[1] The originator'sseal was attachedpendent from the document, so that it did not have to be broken in order for the document to be read.

They are called "letters" (plural) from their Latin namelitterae patentes, used by medieval and later scribes when the documents were written in Latin. This loanword preserves the collective plural "letters" (litterae) that the Latin language uses to denote a message as opposed to a single alphabet letter (littera).^[2]

Letters patent are a form of open or publicproclamation^[3] and a vestigial exercise of extra-parliamentary power by a monarch or president.^{[citation needed]}

They can thus be contrasted with theAct of Parliament, which is in effect a written order by Parliament involvingassent by the monarch in conjunction with its members. No explicit government approval is contained within letters patent, only the seal or signature of the monarch.^{[citation needed]}

Parliament today tolerates only a very narrow exercise of the royal prerogative by issuance of letters patent, and such documents are issued with prior informal government approval, or indeed are now generated by government itself with the monarch's seal affixed as a mere formality. In their original form they were simply written instructions or orders from the sovereign, whose order was law, which were made public to reinforce their effect.^{[citation needed]}

For the sake of good governance, it is of little use if the sovereign appoints a person to a position of authority but does not at the same time inform those over whom such authority is to be exercised of the validity of the appointment.^{[citation needed]}

According to the United KingdomMinistry of Justice, there are 92 different types of letters patent.^[4] ThePatent Rolls are made up of office copies of English (and later United Kingdom) royal letters patent, which run in an almost unbroken series from 1201 to the present day, with most of those to 1625 having been published.^{[citation needed]}

In theUnited Kingdom and otherCommonwealth realms, letters patent are royal proclamations granting an office, right, title, or status to a person (and sometimes in regard to corporations and cities). Letters patent take the form of anopen letter from themonarch to a subject, although this is alegal fiction and they are in fact aroyal decree made under theroyal prerogative and are treated asstatute law.^[5] Letters patent do not require the consent ofparliament.^[6]

Specific usage in Commonwealth realms outside the United Kingdom include:

• Creation of vice-regal offices, for example inCanada in 1947 andNew Zealand in 1983.^[5]
• Creation ofRoyal Commissions or Special Commissions of Inquiry, such as inAustralia.

The primary source of letters patent in theUnited States areintellectual propertypatents andland patents, though letters patent are issued for a variety of other purposes. They function dually as public records and personal certificates.^{[citation needed]}

In the United States, theforgery of letters patent granted by thePresident is acrime subject to fine,imprisonment up to ten years or both (18 U.S.C. § 497). Without letters patent, a person is unable to assume an appointed office. Such an issue prompted theMarbury v. Madison suit, whereWilliam Marbury and three others petitioned theUnited States Supreme Court to orderJames Madison to deliver their letters for appointments made under the previous administration.^{[citation needed]}

United States letters patent generally do not fit a specific form, except for theeschatocol, or formal ending:

^{[citation needed]}

• Commissioning scroll
• Exequatur
• Firman
• Letter of marque
• Lettre de cachet
• Papal bull, a type of letters patent issued by a Pope
• Royal Charter
• Statute of Monopolies 1623, an attempt to rein in the abuse of letters patent in England

• Royal grants in letters patent and charters from 1199, research guide at the National Archives (UK)