Custom As A Source of Law


Custom is one of the oldest sources of law and continues to play an important role in modern legal systems. [1] A custom refers to a habitual or usual practice that has taken on legal force due to long-continued uniformity of acts. [2] Custom emerges from the repeated behaviors of people in society over an extended period. [3] When a specific pattern of conduct becomes widely accepted within a community, it can evolve into a binding custom or rule. [4]

For a practice to qualify as a legally enforceable custom, it must fulfill certain requirements like antiquity, continuity, consistency, certainty, and reasonableness. [5] Courts recognize valid customs as authoritative rules of law. [6] However, customs cannot override statutory laws. [7] Customary law governs various aspects of life in both traditional and modern societies. [8] Many current legal doctrines and concepts have origins in ancient customs. [9]

This paper examines the meaning, evolution, and classification of customs. It analyzes the essential elements of legally valid customs. The paper also discusses different theories about the interaction between custom and formal law. Finally, it provides examples of important customary laws.

Meaning and Evolution of Custom as a Source of Law

The term ‘custom’ has been defined in various ways by different jurists and legal dictionaries. According to Salmond, custom constitutes “the embodiment of those principles which have commended themselves to the national conscience as the principles of justice and public utility”. [10] The Corpus Juris Secundum defines custom as a “usage or practice of the people, which, by common adoption and acquiescence, and by long and unvarying habit, has become compulsory, and has acquired the force of a law with respect to the place or subject-matter to which it relates”. [11]

Customs arise from the repetitive behaviors of members of society. [12] When people face similar situations, they tend to act in certain ways. By constant repetition of particular patterns of conduct over generations, these usages become customs. [13] Initially, customs lack legal force and depend on public opinion for enforcement. [14] But frequent performance gradually invests them with authority until they obtain universal recognition in the community. [15]

At this stage, the custom becomes law and courts enforce it as a binding rule. [16] However, the transformation of custom into law is not automatic. [17] Courts must formally acknowledge a general practice as legally authoritative based on criteria like antiquity, certainty, consistency with statutes, and reasonableness. [18] Mere habitual behavior does not suffice to make a custom legally binding. [19]

Classification of Customs

Customs have been categorized in different ways by jurists. Salmond divided them into legal and conventional customs. [20] Legal customs comprise practices that courts enforce as law. Conventional customs become binding only through contractual incorporation. [21] Dias made a three-fold classification of customs into local, general, and personal. [22] General customs apply nationally whereas local ones operate regionally. [23] Personal customs regulate the conduct of family members or other small groups who carry their traditional usages with them. [24]

Legal customs can be further classified into customary law and custom proper. Customary law refers to an entire body of customs developed by a community to govern various transactions and relationships. [25] Custom proper denotes a specific practice within a locality that differs from the general law. [26] Another common classification distinguishes between customs secundum legem that supplement statutes and customs praeter legem that extend the common law. [27]

Essentials of a Valid Custom

For a custom to have legal validity, it must satisfy certain essential requirements: [28]

  1. Immemorial Antiquity: A valid custom must be ancient and its origin must be obscure and uncertain. English courts presume customs dating from 1189 or earlier to be immemorial. [29] Although Indian courts do not insist on a fixed period, the custom cannot be of recent origin. [30]
  2. Reasonableness: The custom must be fair, certain, and reasonable. [31] Courts deny validity to customs that are uncertain, obsolete or manifestly absurd. [32] However, reasonableness is presumed unless the party challenging the custom proves otherwise. [33]
  3. Certainty: A custom must be precise, definite, and unambiguous. An uncertain, vague or fluctuating practice cannot constitute a legally binding custom. [34]
  4. Consistency: A valid custom must be consistent with statutes. Customs cannot modify or nullify statutory laws. [35]
  5. Continuity: The custom must have been peaceably and freely practiced without interruption. Temporary disregard does not destroy a custom but discontinuance of the right extinguishes it. [36]
  6. Moral Acceptability: An immoral custom is not enforceable. Practices like ritual prostitution, though ancient, are void for being repugnant to morality. [37]
  7. Obligatory Observance: The custom must be regarded as obligatory. Optional practices do not qualify as binding customs. [38]
  8. Conformity with Public Policy: A custom opposing public policy lacks validity. [39]

Theories about Custom as a Law

There are two main schools of thought about the relationship between custom and law: [40]

  1. Historical School: Savigny, Maine, and other proponents of this school believed that custom is an autonomous, primary source of law. In their opinion, laws evolve from pre-existing community practices and convictions about morality. The community practices are evidence of the common consciousness of the people rather than impositions of political superiors. [41]
  2. Analytical School: Austin and Holland, pioneers of this school, propounded that customs by themselves lack legal force. They acquire binding authority only through state recognition and enforcement by courts. In other words, customs originate law but are not laws by themselves. [42]

Salmond and others have attempted to reconcile these opposing theories. They hypothesize that customs grow from community practices but become legally binding only after obtaining judicial or legislative approval. [43] Thus, state recognition and enforcement breathe life into those customs that satisfy essential validity requirements. Mere habitual conduct does not suffice to make a rule legally authoritative. [44]

Examples of Important Customary Laws

Custom constitutes an important source of legal rules and principles in common law countries. Several entrenched legal doctrines have their origins in ancient customs, such as: [45]

  1. Common Law Originating from Customs: The English common law evolved mainly from the customs of the realm. Principles like the rule against perpetuities crystallized from established practices. [46]
  2. International Law Customs: Customary international law forms an important part of public international law. Practices like diplomatic immunity and maritime rules have customary origins. [47]
  3. Constitutional Conventions: While lacking strict legal validity, constitutional conventions exert great influence over the workings of government. They set down customary rules regulating relationships between different branches of government and between the centre and constituent units in a federation. [48]
  4. Customary Personal Laws: Personal laws of Indian communities like Hindus and Muslims still consist largely of their respective customs despite codification. Custom governs many aspects of marriage, adoption, guardianship, succession, joint family structure, and property rights. [49]


In conclusion, custom constitutes one of the most ancient sources of law across different legal systems. General practices initially acquire social sanction through habit and public opinion. When courts formally recognize long-continued customs as legally binding, they get transformed into authoritative rules of law that judges enforce. However, to attain validity, a custom must fulfill certain essential criteria like antiquity, certainty, consistency, and reasonableness. Though an important source historically, customs cannot override statutory laws. Many current legal principles have originated from and continue to be influenced by customs. However, mere habitual conduct is insufficient for a rule to attain status as law. This necessitates state recognition and judicial enforcement of customs.


[1] Hari Chand, Modern Jurisprudence (Allahabad: Central Law Agency, 2001), 170.

[2] Bryan A. Garner, ed., Black’s Law Dictionary, 8th ed. (USA: West Publishing Co., 2004), 412.

[3] Satya Dev Verma, Jurisprudence for Law Students (Allahabad: Central Law Publications, 2010), 154.

[4] SCC Online, “Custom,” accessed February 5, 2023,

[5] Roscoe Pound, Jurisprudence, Vol. 2 (Union, New Jersey: The Lawbook Exchange Ltd., 2000), 367.

[6] N.V. Paranjape, Studies in Jurisprudence and Legal Theory (Allahabad: Central Law Agency, 2001), 290.

[7] Ibid, 291.

[8] SCC Online, “Custom.”

[9] Paranjape, Studies in Jurisprudence, 290.

[10] John Salmond, Jurisprudence, 10th ed. (London: Sweet & Maxwell Ltd., 1947), 183.

[11] Corpus Juris Secundum, vol. 77 (USA: American Law Book Co., 1952), 7.

[12] Verma, Jurisprudence for Law Students, 154.

[13] Paranjape, Studies in Jurisprudence, 289.

[14] Ibid.

[15] Salmond, Jurisprudence, 183.

[16] Paranjape, Studies in Jurisprudence, 290.

[17] Salmond, Jurisprudence, 183.

[18] Paranjape, Studies in Jurisprudence, 290.

[19] Salmond, Jurisprudence, 183.

[20] Ibid, 184.

[21] Paranjape, Studies in Jurisprudence, 290.

[22] R.W.M. Dias, Jurisprudence, 5th ed. (London: Butterworths, 1985), 69.

[23] Ibid.

[24] Ibid.

[25] SCC Online, “Custom.”

[26] Ibid.

[27] Paranjape, Studies in Jurisprudence, 291.

[28] Dias, Jurisprudence, 73.

[29] Paranjape, Studies in Jurisprudence, 290.

[30] Ibid, 291.

[31] Salmond, Jurisprudence, 184.

[32] Dias, Jurisprudence, 73.

[33] Paranjape, Studies in Jurisprudence, 291.

[34] Dias, Jurisprudence, 73.

[35] Paranjape, Studies in Jurisprudence, 291.

[36] Salmond, Jurisprudence, 184.

[37] Dias, Jurisprudence, 73.

[38] Paranjape, Studies in Jurisprudence, 291.

[39] Dias, Jurisprudence, 73.

[40] Chand, Modern Jurisprudence, 171.

[41] Ibid.

[42] Ibid, 172.

[43] Paranjape, Studies in Jurisprudence, 292.

[44] Salmond, Jurisprudence, 183.

[45] Paranjape, Studies in Jurisprudence, 290.

[46] Ibid.

[47] SCC Online, “Custom.”

[48] Ibid.

[49] Paranjape, Studies in Jurisprudence, 290.

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