Leeds University Library

Statutory Instruments

Acts of Parliament cannot always cover every rule and regulation for every detail of the subject they deal with. Acts will often specify details that may subsequently need updating - eg fees, time limits, charges, etc.

To enable the government to update these matters without passing a new Act of Parliament each time, an Act will often confer powers for the making of more detailed rules, orders or regulations by means of Statutory Instruments (SIs). These rules are often called secondary, delegated or subordinate legislation.

Statutory Instruments have the full force of law and are as much a part of the law as the accompanying Act of Parliament. Around 3,000 are issued every year and each contains an explanatory note explaining its scope and purpose.

Each Statutory Instrument is numbered according to the calendar year, and a new sequence begins annually. Therefore when citing a Statutory Instrument you must give the year and number.
eg SI 2012 No.50 The Closure of Prisons Order

Finding Statutory Instruments

  • 1987 to date: Legislation.gov.uk contains the full text of all SIs from 1987 onwards. It also contains a selection of SIs from 1948-1986
  • Westlaw-UK: database including the full text of UK Statutory Instruments in force
  • Lexis Library: database containing the full amended text of all SIs in force in England and Wales
  • 1946-2009: the Library has bound volumes of Statutory Instruments in the Library store.


Statutory Instruments in the Official Publications section are not entered individually in the Library Catalogue.

Use these indexes to find a reference to the SI you want:

  • The final bound volume of Statutory Instruments for a particular year contains a numerical annual index and a subject annual index
  • Halsbury's Statutory Instruments
    A complete classification of all Statutory Instruments in force, including some in full text and many others in summary. It consists of multi volumes arranged in broad subject categories. The volumes are updated in loose-leaf binders, and are periodically reissued when the number of changes warrants it. The annual consolidated index and alphabetical list of instruments, and the chronological list of instruments include all the Statutory Instruments in the volumes and the service.
    Located in the Edward Boyle Library on level 8.
  • The Daily List of government publications is the first official notice of the existence of a Statutory Instrument, giving full details including the date of commencement.