This is a category for all the small railways which were neither:
- included in the 1923 Grouping (see Category:Great Western Railway, Category:London and North Eastern Railway, Category:London, Midland and Scottish Railway or Category:Southern Railway (Great Britain))
- included in the London Underground (see Category:London Underground)
- joint lines (see Category:British joint railway companies)
- absorbed by any railway which falls into the above categories
Railways which were not grouped, but did become part of British Railways, are within the scope of this category.
This category has the following 13 subcategories, out of 13 total.