K.S. Puttaswamy v. Union of India (Aadhaar)

The story

K.S. Puttaswamy, a retired judge, along with civil society activists, took on the Union of India over Aadhaar — a scheme that had quietly become near-mandatory for opening bank accounts, buying SIM cards, filing taxes, and receiving subsidies. They warned of a surveillance state where a single biometric database could track every citizen's life. The government countered that Aadhaar plugged massive leakages in welfare delivery, ensuring food and fuel subsidies reached the poor instead of being siphoned off by middlemen. After marathon hearings, the five-judge bench split: four judges upheld Aadhaar's use for welfare delivery as constitutionally sound, recognizing its anti-poverty potential, but firmly rejected its creeping expansion into private life — banks and telecom companies could no longer hold citizens hostage to Aadhaar enrollment. Justice Chandrachud, alone, dissented in full, warning that the entire architecture threatened constitutional democracy and that passing it as a Money Bill was a fraud on the Constitution. The judgment became a defining moment in India's privacy jurisprudence, balancing welfare state ambitions against individual liberty, though debates about surveillance, exclusion errors, and the Money Bill route continued to simmer long after the verdict.

The facts

Petitioners, led by former Karnataka High Court judge K.S. Puttaswamy, challenged the constitutional validity of the Aadhaar Act, 2016, which established a biometric-based unique identity number (Aadhaar) and mandated its linkage to welfare benefits, bank accounts, mobile SIM cards, and tax filings (PAN). They argued the scheme created a surveillance state, violated the right to privacy and dignity, enabled unauthorized data sharing with private entities, and was improperly enacted as a Money Bill to bypass the Rajya Sabha. The government defended it as necessary for efficient, leak-proof delivery of subsidies and benefits to the poor.

The question before the court

Whether the Aadhaar scheme and the mandatory linking of Aadhaar to various services violate the fundamental right to privacy under Article 21, and whether the Aadhaar Act was validly passed as a Money Bill under Article 110.

The holding

By a 4:1 majority (Sikri J. for the majority; Chandrachud J. dissenting), the Supreme Court upheld the core constitutional validity of the Aadhaar Act, holding that linking Aadhaar to welfare subsidies and benefits under Article 21's mandate to ensure dignified life for the poor was a proportionate restriction on privacy. However, the Court struck down Section 57 (which permitted private companies and individuals to demand Aadhaar authentication), and held that mandatory linking of Aadhaar with bank accounts and mobile SIM cards was unconstitutional and disproportionate. It also upheld the Act's passage as a Money Bill, a conclusion later doubted by a subsequent Constitution Bench in Rojer Mathew v. South Indian Bank (2019).

The principle it stands for

The right to privacy under Article 21 is not absolute and may be restricted by a law satisfying the tripartite test of legality, legitimate state aim, and proportionality. State-mandated biometric identification for targeted delivery of welfare benefits to prevent leakage and ensure dignity can constitute a legitimate, proportionate restriction on privacy, but extending such mandatory identification to private commercial transactions or non-welfare contexts (e.g., bank accounts, SIM cards) fails the proportionality test and violates Article 21.

Provisions this case shaped

• Art. 21Protection of life and personal libertyinterpreted — Privacy and dignity balanced against welfare-state justification under Article 21.
• Art. 110Definition of “Money Bills”upheld — Aadhaar Act's passage as a Money Bill was upheld, though later doubted in Rojer Mathew (2019).