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Ordnance Survey Mapping

The Ordnance Survey is the national mapping agency of Great Britain. We hold the most comprehensive, publicly accessible collection of Ordnance Survey maps in the world. We also hold Ordnance Survey of Northern Ireland (OSNI) and Ordnance Survey of Ireland Maps (OSI).

Pre-war Large Scale Editions (5', 25" and 6" to the mile)

The most frequently consulted items are the large scale plans, which began to be published in the mid-19th century as the 25 and 6 inches to the mile County Series (c.1:2500 and 1:10,560), and town plans at larger scales. They show the landscape in great detail. All pre-WW2 1:2500 editions are now available on microfiche. These are organised by county then sheet number. For a comprehensive guide go to:

Guide to large scale Ordnance Survey maps of Great Britain

Guide to large scale Ordnance Survey maps of Ireland

These tables give information on the dates of each edition for a particular area, and also if they exist in microfiche/film. The advantage of microfiche/film is that it is easy to take copies from.

List of 25" County Editions for England and Wales, Excluding London

List of 6", 25" and 5' London Editions with Index Maps

Post-war Large Scale Editions

Since WWII, the modern equivalent of county series mapping has been the National Grid series at scales of 1:10,560/1:10,000 for rural and moorland areas, 1:2,500 and 1:1250 for urban areas (c.6 inches to 1 mile, c.25 inches to 1 mile and c.50 inches to 1 mile). The National Grid is a single grid system covering Great Britain. From c.1946 until about 1980 the maps were produced on paper sheets; between 1980 and until 1999 the maps were supplied on microfiche. Since 1997 Ordnance Survey has supplied the Legal Deposit Libraries with digital mapping, namely LandLine® and then Ordnance Survey MasterMap ® data.

To determine the grid reference for the map you require use the county indexes available in the Maps Reading Room or go to the 'Get-a map' service on the the Ordnance Survey website. Type in a placename or postcode and a 2 letter, 6 digit grid reference will display eg. TQ 324412. To get a 1:2500 sheet number remove the 3rd and 6th digits, e.g. TQ3241.

Small Scale (2" to the mile, 1" to the mile or 1:50,000) Ordnance Survey

The first small scale maps are the Ordnance Surveyors Drawings between 1789 and 1840. They are generally made at 2" to the mile and cover England and Wales as far north as a line from Preston to Hull. They were followed by the 1" to the mile survey which later became the 1:50,000 series, on national grid lines. For a comprehensive guide go to:

Guide to Small Scale OS Maps

Ordnance Survey Resources for Environmental Site Researchers

Site researchers into the incidence of contaminated land etc. are very welcome to visit the Maps Reading Room. Resources available include a comprehensive collection of large scale Ordnance Survey plans for Great Britain and Ireland dating back to the mid-nineteenth century. This includes post World War 2 National Grid paper sheets until the 1980s, microfilm aperture cards from the 1980s until 1997 and a digital data terminal from 1997 onwards. Large scale OS plans are also available for Northern Ireland and Eire.

The Maps Reading room has a rapid copy service tailored to the needs of site researchers. For Ordnance Survey maps in copyright, i.e. published less than 50 years ago, one A4 from each tile or sheet can be supplied without permission from the Ordnance Survey. Up to 50 copies can be produced within 45 minutes. A4 sheets from microfiche or film of Pre-WW2 large scale county Series maps and National Grid sheets on aperture cards can be obtained instantly from self-service reader-printers. There is no restriction on the quantity of A4 sheets for Ordnance Survey maps published more than 50 years ago. We regret that printouts from digital data are not available to commercial users for copyright reasons. Forthcoming national legislation will also restrict the copying of extracts from all Ordnance Survey maps that are in copyright to non-commercial users and the British Library reserves the right to refuse copies of any Ordnance Survey maps that are less than 50 years old to commercial users who cannot demonstrate they have permission to copy from Ordnance Survey.


Examples of different scales of OS maps

Guide to Large Scale OS Maps in the British Library

25" County Series Editions List

5', 25" and 6" London Editions List

Guide to Small Scale OS Maps in the British Library

Guide to large scale Ordnance Survey maps of Ireland

Cartographic sources for rights of way evidence in England and Wales

Cartographic sources for dating houses in England and Wales


Ordnance Survey (Great Britain)

Ordnance Survey of Northern Ireland

Ordnance Survey of Ireland

Charles Close Society - A society dedicated to the study of OS mapping

Old-maps 19th century, 25" and 6" OS maps. Place name search to 1:50,000.

David Archer Maps Map dealer specialising in old OS maps.