What's the correct CRS for the Ordnance Survey Open Data Products? The spatialreference website shows a number of projections identified as British National Grid:

SR-ORG:6812: BritishNatGrid
SR-ORG:6832: UK National Grid
SR-ORG:6971: Great Britain National Grid with additional Helmert Corrections
SR-ORG:7132: uk nat grid
SR-ORG:7237: test
SR-ORG:7340: test
EPSG:7405: OSGB36 / British National Grid + ODN height
SR-ORG:7415: ordinance survey boundry-line
SR-ORG:7460: osgb:BNG
EPSG:27291: NZGD49 / North Island Grid
EPSG:27292: NZGD49 / South Island Grid
EPSG:27700: OSGB 1936 / British National Grid
  • 3
    EPSG:27700: OSGB 1936 / British National Grid
    – T_Bacon
    Dec 29, 2016 at 9:04
  • @T_Bacon Thank you very much; I wanted to find proj4js string to use it in r while importing boundary shapefiles via readOGR.
    – Konrad
    Dec 29, 2016 at 9:07
  • Why the heck is it listing two New Zealand CRS??
    – mkennedy
    Dec 29, 2016 at 20:16

1 Answer 1


The EPSG code for OS products is epsg:27700. If you need further formats (though that should be enough for any good GIS) you can visit http://epsg.io/27700 which will allow you to download a specific format such as proj.4 directly.

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