Expressio unius est exclusio alterius means that what a statute mentions expressly in one place and omits in a comparable place was left out deliberately. It is an aid to finding legislative intent, not a rule of law.
In 2025 the Supreme Court took this maxim in two directions within a single term. In Dr. Sharmad v. State of Kerala, it held that a promotion rule which demanded post-qualification experience for one cadre and said nothing about it for the other had dropped that requirement on purpose. That April, in Md. Firoz Ahmad Khalid v. State of Manipur, it held that the same maxim had “absolutely no application”, because reading the omission as an exclusion would have produced an unreasonable and unjust classification. Anyone arguing this maxim has to be able to explain the difference between those two results.
This article sets out what expressio unius est exclusio alterius means and when a court will apply it. It also covers the limits the courts have placed on it.
The maxim only starts to do any work once a statute has said something expressly and then gone quiet about the neighbouring case, so a worked example has to begin there. Take a licensing statute which says that a licence may be cancelled on three grounds, namely a false declaration in the application, a breach of a condition endorsed on the licence, and a conviction for an offence under the Act.
The authority cancels a licence on a fourth ground altogether, which is that the holder has stopped carrying on the business the licence was granted for. The holder’s answer is that the section names three grounds and no more.
Whether that answer works turns on whether the three grounds read as the complete set the legislature had in mind or merely as examples of it. If the enumeration is closed, and nothing elsewhere in the Act gives the authority a general power of cancellation, the omission counts as deliberate and the cancellation falls. If the Act does carry a general power, the three named grounds sit alongside it and the maxim never gets off the ground.
The implied exclusion that expressio unius est exclusio alterius creates
The exclusion that expressio unius est exclusio alterius creates is an inference, which is that whatever the legislature left out of an express list, it left out on purpose. The maxim translates as the expression of one thing is the exclusion of another, and a court uses it to turn a statutory silence into a positive finding about what the statute means. The silence is not treated as a gap in the Act, but as a decision the drafter took.
That inference is an aid to construction and not a rule of law, and almost everything else about the maxim follows from that one point. A rule of law binds a court whatever the consequences, whereas an aid to construction only helps a court find the legislature’s intention, so it yields the moment better evidence of that intention turns up. It therefore sits among the rules of interpretation that assist a judge rather than among those that bind one, and it argues from what a statute does not say.
The maxim also works only on the statute’s own text. A court applying it is not asking whether the omitted case ought to be covered as a matter of policy, because that question belongs to the legislature. It asks something narrower, which is whether the drafter, having dealt with one situation in express terms, must be taken to have considered the neighbouring situation and decided against it.
How a court draws the exclusion from the statute’s own structure
A court draws the exclusion by comparing what the statute says in one place against what it does not say in a comparable place. The comparison is internal to the Act, and the closer together the two provisions sit, the stronger the inference gets.
The strongest form of that comparison is two limbs of a single provision, drafted in parallel, where one limb carries a qualifying phrase and the other does not. A drafter who writes the same words twice and then drops them the third time has done something visible on the face of the section. The weakest form is a comparison across two unrelated statutes passed years apart by different drafting teams, where the difference in wording may say nothing at all about anyone’s intention.
The express mention also has to sit in a context which suggests the drafter was working to a complete set. Where a provision reads as though the legislature set out to name everything that qualifies, the absence of an item from that list is significant. Where the provision reads as though the legislature named a few obvious cases and left everything else to a general power, the same absence proves nothing.
Because the whole exercise is an argument about intention, it gives way to anything which shows that intention more directly. A definition clause, an explanation, a proviso, the long title, or the history of an amendment can each displace the inference, and a court will prefer any of them to a bare argument from silence.
One limit belongs here rather than later, because it ends an argument before the remaining tests are reached. The maxim answers a question which the text has left open, and it does not override text that already answers the question on its own. Where the words of the section are plain enough to decide the case, a court has no occasion to reason from what the section leaves out, and an appeal to the maxim at that stage is simply misplaced.
The exclusion the Supreme Court read into the Kerala promotion rules
In Dr. Sharmad v. State of Kerala, decided in January 2025, the Supreme Court read the silence in one column of a recruitment rule as a deliberate exclusion. The judgment is reported as 2025 INSC 70.
The Special Rules governing the Kerala Medical Education Service set out eligibility for promotion in two branches of the same service. Branch I covers the administrative cadre and Branch II covers the teaching cadre. The dispute was whether the five years of physical teaching experience required for promotion in the teaching cadre had to be acquired after the candidate obtained the postgraduate or super specialty degree.
What decided the case was a difference between two columns of the same set of rules. The experience column for the administrative cadre posts expressly required the experience to be acquired after a postgraduate degree, and the corresponding column for the teaching cadre posts carried no such words. The rule framer had therefore shown, inside the same instrument, that it knew how to impose a post-qualification requirement whenever it wanted one.
On that footing the Division Bench held: “This is a case where the maxim expressio unius est exclusio alterius … would apply.” The absence of the qualifying words was read as a decision rather than an oversight, so no post-qualification requirement could be written into the teaching cadre column. The Court set aside the High Court’s judgment, restored the Tribunal’s order, and upheld the promotion.
The inference was safe here for three reasons which rarely come together. The two provisions sat in one instrument, and they had been drafted in parallel for the same purpose. The qualifying phrase was then present in one and absent from the other in identical drafting positions. Strip any of those away and the argument weakens considerably.
The conditions a court tests before applying expressio unius est exclusio alterius
A court tests two things before it applies expressio unius est exclusio alterius. The first is whether the express list is exhaustive rather than illustrative. The second is whether the omission was deliberate rather than accidental, and that second test is where most of the argument happens.
The exhaustiveness test comes first because it is capable of ending the enquiry outright. Where the enumeration reads as illustrative, the presumption weakens to nothing, since a list of examples says nothing about whatever it does not mention. Words such as “including”, “such as”, and “and the like” mark a list as open, and so does an enumeration which is plainly a sample of a wider category.
A general power sitting elsewhere in the Act points the same way. If the statute confers a residual or overriding power on the same authority, a specific list is naturally read as an illustration of that power rather than as a limit on it, and the maxim cannot then be used to cut the power down. That is why the first thing to do with an expressio unius argument is to read the rest of the Act rather than the section in dispute.
Statutes which are read strictly give the maxim more room to operate. In a taxing or penal statute a court will not extend the words beyond what they say, so a case the provision does not mention is more readily treated as falling outside it. The two column structure in Dr. Sharmad sits at the same end of the scale for a different reason, which is that a closed tabular rule leaves very little space for the argument that something was accidentally left out.
When an express mention shows a deliberate exclusion
An express mention shows a deliberate exclusion when the omission cannot fairly be explained as inadvertence or accident. It comes from the case which gave the maxim its most quoted warning.
In Colquhoun v. Brooks, (1888) 21 QBD 52, Lopes L.J. said of the maxim that “it is often a valuable servant, but a dangerous master to follow in the construction of statutes or documents. The exclusion is often the result of inadvertence or accident, and the maxim ought not to be applied, when its application, having regard to the subject matter to which it is to be applied, leads to inconsistency or injustice.” Indian courts have relied on that sentence for well over a century.
So how does a court tell inadvertence from intention? The most reliable indicator is internal symmetry. Where a drafter has used a phrase in three neighbouring places and dropped it in the fourth, accident becomes hard to argue, because a slip of that kind would have to have been repeated consistently in exactly one position.
Amendment history does similar work, and it is often stronger. Where a qualifying phrase once appeared in a provision and was removed by a later amending Act, the removal is a positive act of the legislature rather than a silence, and a court can treat it as such. The same is true where Parliament added the phrase to one provision in an amendment and left the neighbouring provision untouched.
The burden sits on the party asserting the exclusion. It is not enough to show that the statute is silent, because every statute is silent about a very large number of things. Counsel has to show that the silence is of a kind which the drafting itself explains.
The maxim also has to be kept apart from casus omissus, which starts from the same silence and pulls in the opposite direction. Casus omissus asks whether a court may supply something the legislature has left out of a statute. Expressio unius asks whether the court is bound to respect the omission as a choice. The two doctrines meet on identical facts, so an argument which fails under one is regularly reframed under the other.
The limits on expressio unius est exclusio alterius
The maxim stops wherever the ordinary tools of construction already answer the question, and wherever the exclusion it would produce is unjust or absurd. Both limits are old, and both are applied often enough that no expressio unius argument should be made without addressing them.
Lopes L.J.’s description of the maxim as a valuable servant but a dangerous master is the source of the caution, and Indian law adopted it early. The Supreme Court carried the formulation into Indian jurisprudence in Assistant Collector, Central Excise v. National Tobacco Co. of India Ltd., (1972) 2 SCC 560, and it relied on that authority again in 2025, alongside State of Karnataka v. Union of India, (1977) 4 SCC 608.
The reason a maxim of this kind can never be more than a guide is structural. Every application of it is an inference drawn from silence, and silence is the weakest evidence a statute offers about its own meaning, because a legislature may be silent for reasons which have nothing to do with an intention to exclude. Drafting compression, a change of policy midway through a Bill, and plain oversight all produce the same silence on the page.
Where the courts have refused to read in an exclusion
The courts have refused the maxim in two recurring situations.
The first is where the statutory language is already plain. In Parbhani Transport Co-operative Society Ltd. v. Regional Transport Authority, Aurangabad, AIR 1960 SC 801, the Supreme Court said that the maxim “is a maxim for ascertaining the intention of the legislature. Where the statutory language is plain and the meaning clear, there is no scope for applying the rule.” The Motor Vehicles Act, 1939 provided for the grant of permits under Chapter IV, and it made separate provision for State transport undertakings under Chapter IVA. The argument was that the special route in Chapter IVA impliedly barred the Government from applying for an ordinary permit under Chapter IV.
The Court rejected it. Where a statute itself provides two modes of doing the same thing, the existence of the second mode does not imply a prohibition on using the first. The plain language of these provisions left no room for reading in a bar which the Act had not enacted.
The second situation is where applying the maxim would produce an unreasonable classification. That is what happened in Md. Firoz Ahmad Khalid v. State of Manipur, 2025 INSC 535, on Section 14(1)(b)(iii) of the Wakf Act, 1995 and Explanation II to it. At paragraph 16 the Court held that “the legal maxim ‘expressio unius est exclusio alterius’ finds absolutely no application to the instant case, as applying the same would render an interpretation contrary to the intent of the provision, resulting in an unreasonable and unjust classification.”
Read together with Dr. Sharmad, the two 2025 judgments mark out the working range of the maxim. It carries weight where a single instrument treats two comparable cases differently and the difference is visible in the drafting. It carries none where the words already decide the question, or where the exclusion would put two similarly placed classes on a different footing for no reason the statute supplies.
Frequently asked questions
Is expressio unius est exclusio alterius a rule of law or a rule of construction?
It is a rule of construction. The Supreme Court described it in Parbhani Transport as a maxim for ascertaining the intention of the legislature, so it helps a court find intention and does not bind the court where the intention appears from something else in the Act.
What is the difference between expressio unius est exclusio alterius and casus omissus?
Both doctrines start from a statutory silence and pull in opposite directions. Casus omissus asks whether a court may supply something the legislature has left out, and the general answer is that it may not. Expressio unius asks whether the court is bound to treat that same omission as a deliberate exclusion.
Does expressio unius est exclusio alterius apply when a statute lists things only as examples?
It does not apply to an illustrative list, and that is the commonest reason the argument fails. Words such as “including” or “such as”, or a general power sitting elsewhere in the Act, mark the list as open, and an open list carries no implication about anything it does not mention.
Which Supreme Court judgment most recently applied expressio unius est exclusio alterius?
Dr. Sharmad v. State of Kerala, 2025 INSC 70, decided in January 2025, is the most recent reported application. The Kerala Medical Education Service rules required experience acquired after a postgraduate degree for the administrative cadre and said nothing to that effect for the teaching cadre, and the Court held that omission deliberate.
References
- Dr. Sharmad v. State of Kerala, 2025 INSC 70, Supreme Court of India, judgment dated 10 January 2025 (maxim applied to the Kerala Medical Education Service Special Rules).
- Md. Firoz Ahmad Khalid v. State of Manipur, 2025 INSC 535, Supreme Court of India, judgment dated 22 April 2025 (paragraph 16; maxim held inapplicable to Section 14(1)(b)(iii) of the Wakf Act, 1995).
- Parbhani Transport Co-operative Society Ltd. v. Regional Transport Authority, Aurangabad, AIR 1960 SC 801, Supreme Court of India, judgment dated 7 March 1960 (Motor Vehicles Act, 1939, Chapters IV and IVA).
- Colquhoun v. Brooks, (1888) 21 QBD 52 (Lopes L.J. on the maxim as a valuable servant and a dangerous master).
- Assistant Collector, Central Excise v. National Tobacco Co. of India Ltd., (1972) 2 SCC 560, and State of Karnataka v. Union of India, (1977) 4 SCC 608 (Indian adoption of that caution, relied on in Md. Firoz Ahmad Khalid).
This article is for informational and educational purposes only and does not constitute legal advice. Readers should consult a qualified advocate before acting on any point discussed here.