An uncodified constitution is a type of constitution where the fundamental rules often take the form of customs, usage, precedent and a variety of statutes and legal instruments. An understanding of the constitution is obtained through reading commentary by the judiciary, government committees or legal experts. In such a constitutional system, all these elements may be (or may not be) recognized by courts, legislators and the bureaucracy as binding upon government and limiting its powers. Such a framework is sometimes imprecisely called an "unwritten constitution"; however, all the elements of an uncodified constitution are typically written down in a variety of official documents, though not codified in a single document.
An uncodified constitution has the advantages of elasticity, adaptability and resilience, A. V. Dicey described the uncodified constitution as "the most flexible polity in existence." A significant disadvantage, however, is that controversies may arise due to different understandings of the usages and customs that form the fundamental provisions of the constitution.
A new condition or situation of government may be resolved by precedent or passing legislation. Unlike a codified constitution, there are no special procedures for making a constitutional law and it will not be inherently superior to other legislation. A country with an uncodified constitution lacks a specific moment where the principles of its government were deliberately decided. Instead, these are allowed to evolve according to the political and social forces arising throughout its history.
When viewed as a whole system, the difference between a codified and uncodified constitution is one of degree. Any codified constitution will be overlaid with supplementary legislation and customary practice after a period of time. Conversely, customs and practices that have been observed for long periods in an uncodified manner may be added to the written constitution at various junctures, such as in the case of the two-term limit for presidents of the United States. This custom was observed for nearly a century and a half, unbroken, without any enforcement mechanism until it was ignored by Franklin Roosevelt, after which it was added to the written Constitution as mandatory .
Current states
The following states can be considered to have uncodified constitutions.
Canada
Although there are Constitution Acts, important aspects of the constitutional system are uncodified. The preamble to the Constitution of Canada declares it to be "similar in principle to that of the United Kingdom" (which is uncodified).
This applies at the federal level and to the provinces, although each does have the power to modify or enact their own within their exclusive areas of responsibility. To date only British Columbia has enacted a codified provincial constitution (see Constitution of British Columbia), though the other provinces' roles and powers are spelled out in section 93 of the Constitution Act, 1867, and through amendments to it dealing with particular provinces such as the Manitoba Act and the Newfoundland Act.
China
Some Chinese academics including legal theorist Jiang Shigong have argued that China has both a written constitution and an unwritten constitution based on the comprehensive leadership of the Communist Party.
Israel
The Israeli declaration of independence promised a constitution by 2 October 1948, but due to irreconcilable differences in the Knesset, no complete codified constitution has been written yet. There are several Basic Laws, however.
New Zealand
New Zealand has no single constitutional document. It is sometimes referred to as an "unwritten constitution", although the New Zealand constitution is in fact an amalgamation of written and unwritten sources.
The Constitution Act 1986 has a central role, alongside a collection of other statutes, orders in Council, letters patent, decisions of the courts, principles of the Treaty of Waitangi, and unwritten traditions and conventions.
San Marino
San Marino has several documents that make up its constitution, including some lasting centuries. These documents include six books of The Statues of 1600 and the Declarations of Citizen's Rights. It is the oldest surviving constitution in the world.
Saudi Arabia
Saudi Arabia has no legally binding written constitution. In 1960, King Faisal declared the Quran, the religious text of Islam, to be the constitution. However, in 1992, the Basic Law of Saudi Arabia was adopted by royal decree.