Article IV Privileges and Immunities: The Comity Rule

A state tells out-of-state lawyers they may not join its bar unless they move in. Another charges non-resident commercial fishermen a licence fee a hundred times what its own residents pay. Both statutes run into the same one-sentence provision of Article IV, and both are almost certainly unconstitutional.

The Article IV Privileges and Immunities Clause says that the citizens of each state are entitled to all privileges and immunities of citizens in the several states. It is a comity rule: whatever a state gives its own citizens in the way of fundamental rights, it must extend to citizens of sister states. The doctrine is compact, but it has three filters and one very narrow defence, and each of them decides real cases.

Diagram of the Article IV Privileges and Immunities Clause showing the discrimination trigger, the individuals-only limit, the fundamental rights covered and the two-prong justification defence — Fig. 45 · Article IV comity: the trigger, who is protected, what is protected and the defence.

Filter one: there must be discrimination

The clause is an anti-discrimination provision, not a general guarantee of good treatment. If a state law applies identically to residents and non-residents, Article IV drops out of the analysis entirely, however heavy the burden it imposes. A high licence fee charged to everyone raises no comity issue; a lower fee for residents raises nothing else.

That makes the first question mechanical. Compare the treatment of the state’s own citizens with the treatment of citizens of other states. If the answer is the same, stop.

Filter two: only individual citizens are protected

This is the most heavily tested trap in the doctrine. The clause speaks of the “citizens of each State”, and courts have read that literally. Corporations are not citizens for these purposes, and neither are aliens. A company facing plainly protectionist state legislation has no Article IV claim at all.

That is not the end of its case, of course. It has the dormant Commerce Clause, which reaches discrimination against out-of-state commerce regardless of who owns the business. Knowing which claim belongs to which plaintiff is half of what these questions are testing.

Filter three: only rights fundamental to national unity

Not every state-conferred advantage is a privilege or immunity. The protected category, traced to Justice Bushrod Washington’s circuit opinion in Corfield v. Coryell (1823), covers rights fundamental to citizens of all free governments. In modern practice that means two clusters: civil liberties such as access to the courts and freedom of movement, and economic rights bearing on livelihood — employment, professional practice, owning property and carrying on a business.

Recreation sits outside. A state may charge non-residents far more for a hunting or sport-fishing licence, because recreational access to state game is treated as a benefit the state may reserve for those who fund it. The moment the activity becomes a trade rather than a pastime, the analysis flips, which is exactly the line that decided the shrimping cases.

The defence: two prongs, both mandatory

Once discrimination against a protected right is shown, the state carries the burden of justification, and it must satisfy both halves of a demanding test. First, non-residents must be a peculiar source of the evil the state is addressing. Second, the discrimination must bear a substantial relationship to that evil, with no adequate less-discriminatory alternative available.

The first prong does most of the killing. If residents contribute to the same problem, non-residents are not its peculiar source and the defence collapses at once. Toomer v. Witsell (1948) is the leading application: South Carolina defended a hugely disproportionate non-resident shrimp-boat fee as a conservation measure, but resident boats depleted the same stock, and the fee bore no demonstrated relationship to the extra costs the state claimed.

Exam tip: state the burden out loud. The state must prove both prongs. A question that merely asserts that outsiders are “causing the problem” has not begun to satisfy the first one.

Article IV is not the Fourteenth Amendment

Two clauses share almost the same name and almost nothing else. Article IV, Section 2 governs comity between states: it stops State A from treating citizens of State B as second class. The Fourteenth Amendment’s Privileges or Immunities Clause concerns the rights of national citizenship and is the modern home of the right to travel, as Saenz v. Roe (1999) confirmed when it struck down a durational residency limit on welfare benefits.

Question	Which doctrine
State charges out-of-state citizens more to practise a trade	Article IV Privileges and Immunities
State burdens an out-of-state corporation’s business	Dormant Commerce Clause
State pays newcomers lower benefits than long-term residents	Fourteenth Amendment Privileges or Immunities — right to travel
State law burdens residents and non-residents alike	Neither — no discrimination to attack
State reserves cheap sport-fishing licences for residents	Neither — recreation is not a fundamental right
State refuses out-of-state citizens access to its courts	Article IV Privileges and Immunities

Matching the plaintiff and the grievance to the right clause.

Worked example

State M limits commercial fishing licences to its own residents, defending the rule on the ground that out-of-state boats are depleting its fish stocks. Commercial fishermen from State N sue under Article IV.

The fishermen win. Commercial fishing is a livelihood, so a protected privilege; the plaintiffs are individual citizens, so within the clause; and the rule is facially discriminatory, so the trigger is satisfied. The burden shifts to State M, which must show that non-residents are the peculiar source of the depletion. If resident boats fish the same waters and cause comparable depletion — and the record almost always shows they do — the first prong fails and the inquiry is over. Even if it did not, a flat resident-only ban would struggle on the second prong, because catch limits and seasons would address depletion without discriminating at all.

Change one fact. Suppose the plaintiff is a fishing company incorporated in State N rather than an individual. Article IV is unavailable, and the challenge must be repleaded under the dormant Commerce Clause, where the discrimination will very likely still be fatal but the framework and the defences are different.

Common mistakes that cost points

Bringing an Article IV claim on behalf of a corporation or an alien. Neither is a protected citizen.
Assuming every difference in treatment is unconstitutional. Recreational privileges may be reserved for residents.
Forgetting that the clause needs discrimination. A neutral burden, however severe, is outside it.
Confusing Article IV comity with the Fourteenth Amendment right to travel.
Letting the state satisfy the defence by asserting a problem without proving that residents do not cause it too.
Ignoring the less-discriminatory-alternative element inside the second prong.

Frequently asked questions

Does the clause apply to the federal government?

No. It restrains states in their treatment of each other’s citizens. Federal discrimination between residents of different states raises different questions, generally under equal protection principles applied to the federal government through the Fifth Amendment.

Are residency requirements for public employment always invalid?

Not always, but they are vulnerable. A requirement that municipal employees live in the city has been sustained in some settings on the strength of genuine local justifications, while blanket resident-preference schemes for private construction work have failed. The analysis is always the two-prong test, applied on the record.

Can a state charge non-residents higher tuition at its universities?

Generally yes. Subsidised tuition is treated as a benefit funded by resident taxpayers rather than a right fundamental to national unity, so a bona fide residency classification for tuition purposes survives.

Article IV privileges and immunities in Los Angeles County, 2026

This clause restrains discrimination against citizens of other states in matters fundamental to the national union, principally the pursuit of a livelihood. The Los Angeles connection is direct, because the leading municipal case involved exactly the kind of ordinance large California cities favour.

In United Building and Construction Trades Council v. Camden (1984) the Court held that a municipal ordinance requiring a percentage of workers on city-funded construction projects to be city residents was subject to the clause, even though it burdened in-state non-residents as well as out-of-state ones. Local hire requirements attached to public works and project labour agreements in Los Angeles therefore sit within the doctrine’s reach and must be justified by a substantial reason with a close relation between the discrimination and the evil addressed.

How the analysis runs locally:

Livelihood is the protected interest. Employment, professional practice and commercial activity qualify; recreational licences generally do not.
Higher fees for non-resident hunting and fishing survive. Recreation is not fundamental, so differential pricing is permissible.
Bar admission cannot require residency. The State Bar of California admits qualified applicants without a residence requirement, consistent with the clause.
The market participant exception does not apply. Unlike the dormant Commerce Clause, spending its own money does not exempt the county or city here.
Corporations and aliens are outside the clause. Only citizens are protected, so corporate plaintiffs must use the Commerce Clause instead.
Substantial reason means evidence. A city defending local hire must show unemployment data or spillover effects, not merely assert local benefit.

For 2026, ask whether the burdened interest is fundamental and then whether the discrimination is closely tailored to a real problem. Read with the dormant Commerce Clause, the right to travel and equal protection.

Next steps

Read this beside the dormant Commerce Clause, which handles the claims corporations must bring, then the Supremacy Clause and federal preemption for conflicts with federal law, and the three levels of scrutiny for the standards that govern discrimination claims elsewhere in the Constitution.

For primary sources, read Toomer v. Witsell on Justia and Saenz v. Roe also on Justia, review Article IV on Cornell Legal Information Institute, and confirm current subject coverage with the State Bar of California.