The total route mileage was 6,590 miles (10,610 km). The North Eastern Railway had the largest route mileage, 1,757 miles (2,828 km), the Hull and Barnsley Railway just 106.5 miles (171.4 km).
It covered the area north and east of London. It included the East Coast Main Line from London to Edinburgh via York and Newcastle upon Tyne and the routes from Edinburgh to Aberdeen and Inverness. Most of the country east of the Pennines was within its purview, including East Anglia. The main workshops were in Doncaster, with others at Darlington, Inverurie and Stratford, London.
The LNER inherited four of London's termini: Fenchurch Street (ex-London and Blackwall Railway; King's Cross (ex-Great Northern Railway); Liverpool Street (ex-Great Eastern Railway); and Marylebone (ex-Great Central Railway). In addition, it ran suburban services to Broad Street (London, Midland and Scottish Railway) and Moorgate (Metropolitan Railway, later London Transport).
The LNER owned: