OS stands for Original Side — the jurisdiction through which certain High Courts in India directly hear and try cases as courts of first instance, rather than only hearing appeals from subordinate courts. In an OS proceeding, the High Court functions not as an appellate court but as the trial court itself — entertaining cases filed directly before it.
Not all High Courts have Original Side jurisdiction. In India, the High Courts of Calcutta, Bombay, and Madras historically had Original Side jurisdiction — inherited from the Royal Charters that established these courts during the colonial era. These courts try certain categories of civil cases directly, without the matter first being heard by a subordinate court.
Historical Origin of OS Jurisdiction
The Original Side jurisdiction of Indian High Courts traces back to the colonial era. When the High Courts of Calcutta, Bombay, and Madras were established under the High Courts Act, 1861 (replacing the old Supreme Courts), they retained the original civil jurisdiction that the old Supreme Courts exercised over certain categories of persons and matters within their respective town limits.
The Letters Patent issued to each High Court defined their original jurisdiction — the types of cases they could hear directly and the territorial and pecuniary limits of that jurisdiction. This is why LPA (Letter Patent Appeal) lies against OS decisions — these appeals are specifically provided for in the Letters Patent.
Categories of Cases on the Original Side
Company Matters High Courts exercise original jurisdiction over company law matters — winding up petitions, oppression and mismanagement petitions, merger/amalgamation approvals. After NCLT was established under the Companies Act, 2013, much of this work transferred. However, High Courts retain some original jurisdiction in company matters.
Testamentary Matters Grant of probate (confirmation of wills) and letters of administration (for intestate estates) are OS matters in High Courts having original jurisdiction.
Admiralty and Maritime Matters Cases involving ships, maritime contracts, and maritime liens are heard on the Original Side — particularly in Bombay and Calcutta, which are major port cities.
Matrimonial Matters Certain matrimonial cases between parties within specified town limits fall under OS jurisdiction.
Civil Suits Above Specified Pecuniary Limits In some High Courts, ordinary civil suits above a prescribed monetary value filed by parties within the court’s original jurisdiction territory are heard on the OS.
OS vs. AS — The Critical Distinction
| Feature | OS (Original Side) | AS (Appellate Side) |
| Nature of Jurisdiction | Original — trial court function | Appellate — reviewing lower court decisions |
| How Cases Enter | Filed directly in High Court | Appeal from District Court / other courts |
| Procedure | Regular civil/company procedure | Appellate review procedure |
| Law Officers | Government Pleader (OS) | Advocate General / AAG / AGA |
| Available in | Only select High Courts | All High Courts |
Frequently Asked Questions (FAQs)
Q: What is the full form of OS in law?
A: OS stands for Original Side — the jurisdiction of certain High Courts (Calcutta, Bombay, Madras) to hear and try cases directly as courts of first instance, without the matter first being heard in a subordinate court.
Q: Which High Courts have Original Side jurisdiction?
A: Historically, Calcutta, Bombay, and Madras High Courts have OS jurisdiction — inherited from colonial-era Royal Charters. The Delhi High Court also exercises some original jurisdiction in company matters.
Q: What types of cases are heard on the Original Side?
A: Company matters, testamentary cases (probate, letters of administration), admiralty and maritime matters, and certain high-value civil suits within the court’s territorial jurisdiction.
Q: What is the difference between OS and AS?
A: OS (Original Side) is where the High Court acts as a trial court hearing cases directly. AS (Appellate Side) is where the High Court hears appeals from subordinate courts.
Q: How is an appeal filed against an OS decision?
A: An OS decision is appealed through a Letters Patent Appeal (LPA) — an intra-court appeal before the Division Bench of the same High Court.
Q: What are Letters Patent?
A: Letters Patent were royal charters issued by the British Crown establishing the High Courts and defining their powers — including the original jurisdiction that forms the basis of OS proceedings today.
Q: What is a Government Pleader (Original Side)?
A: The Government Pleader (OS) is a law officer who handles government matters specifically on the Original Side of the High Court — distinct from the Advocate General who handles appellate side matters.
Q: What happened to Original Side company jurisdiction after NCLT?
A: When the National Company Law Tribunal (NCLT) was established under the Companies Act, 2013, much of the company-related OS jurisdiction of High Courts transferred to NCLT. High Courts retain appellate jurisdiction through NCLAT.
