| Letter | Train Company | Destination Area |
| A | South Central | London Victoria and Brighton. |
| B | South Central | London Bridge (Sussex side) and Brighton/Reigate via Forest Hill (not range 1B31-1B70).
London Victoria and Epsom Downs via Hackbridge. |
| B | Connex South Eastern | London Bridge (Sussex side) and Tunbridge Wells via Redhill (range 1B31-1B60). |
| B | Thameslink | London Bridge (Sussex side) and Brighton via Forst Hill (range 1B61-1B70). |
| C | South Central | London and West Coast via Crawley. London Victoria and Reigate. |
| D | Gatwick Express Ltd | London Victoria to Gatwick Airport (one direction only, Class 2 not available). |
| D | South Central | Brighton and Hastings (both directions), Portsmouth to Hastings (Cross Brighton - one direction only), (Class 1 not available). London Bridge and Sutton via Wimbledon (Class 1 not available). |
| D | South West Trains | London Waterloo and Dorking via Epsom. |
| E | South Central | London and Horsham/West Sussex/Epsom Downs via Hackbridge (Class 1 not available)
Brighton and Bognor Regis via Littlehampton or direct (both directions, not Littlehampton and Bognor Regis locals), Hastings/Seaford to Bognor Regis via Littlehampton (Cross Brighton, one direction only) (Class 1 not available). Oxted and Uckfield. |
| F | South Central | London and East Coast (Class 2 not available).
Brighton and Seaford (both directions), Bognor Regis to Seaford via Littlehampton (Cross Brighton, one direction only) (Class 1 not available). London Victoria and London Bridge via Crystal Palace (Class 1 not available). London Victoria and Tattenham Corner (via Fls) (Class 2 only). |
| G | South Central | London Bridge and Caterham/Tattenham Corner. |
| H | South Central | London and West Coast via Hove (Class 2 not available).
London Victoria/London Bridge and Beckenham Junction (Class 1 not available). Barnham and Bognor Regis (Class 1 not available). ECS London Victoria to Streatham Hill (one direction only). |
| H | Connex South Eastern | Charing Cross/Cannon Street and Ore via Sevenoaks.
ECS St. Leonards WM CSD and Ore. |
| J | South Central | London Bridge and West Croydon via Streatham Common. |
| J | Thameslink | St. Albans and Selhurst via Herne Hill and Streatham Common. |
| J | Connex South Eastern | Three Bridges to Strood (one direction only). |
| K | South Central | London Bridge and East Croydon via Streatham Common or Crystal Palace.
London Bridge and West Croydon via Crystal Palace. ECS London Bridge to Selhurst T&RSMD via Streatham Common (one direction only). |
| L | South Central | London and East Grinstead/Uckfield (not Oxted to Uckfield locals). |
| M | South Central | Brighton to Watford (one direction only) (no longer used). |
| M | Any | Other trains to North West/Midland Zone destinations (not Thameslink) (one direction only). |
| N | South Central | Eastbourne/Seaford/Brighton and Portsmouth/Southampton/Bournemouth (not trains running only east of Barnham).
London Bridge and London Victoria via Atlantic Line. London Bridge and London Victoria via Crystal Palace and Tulse Hill. ECS London Bridge to Streatham Hill via Crystal Palace (one direction only). |
| N | South West Trains | Brighton and Portsmouth. |
| O | South Central | Watford to Brighton (one direction only). |
| O | Connex South Eastern | Gillingham to Three Bridges (one direction only). |
| O | South West Trains | Reading/Paignton to Brighton via Havant (one direction only). |
| O | Thames | Oxford/Reading to Gatwick Airport (one direction only). |
| O | Thameslink | Bedford and Sutton via St. Helier or Hackbridge (both directions). |
| O | Any | Other trains to Southern Region (one direction only). |
| P | South Central | London Victoria and Tattenham Corner via Streatham Common or Crystal Palace.
Littlehampton and Bognor Regis. ECS London Victoria to Selhurst T&RSMD (one direction only). |
| R | South Central | London Victoria and Epsom Downs/Guildford/Dorking via Norbury.
Hastings and Bognor Regis via Littlehampton (Cross Brighton, not locals). |
| S | South Central | London Victoria and Epsom via Crystal Palace and West Croydon.
To Scotland Zone destinations (one direction only). |
| T | Thameslink | Bedford and Brighton via London Bridge. |
| T | Gatwick Express Ltd | London Victoria (Sussex side) and Stewarts Lane ECS. |
| T | South Central | Eastbourne and Ashford (Kent). |
| U | Gatwick Express Ltd | Gatwick Airport to London Victoria (one direction only) (Class 2 not available). |
| U | South Central | London Bridge and Epsom Downs/Guildford/Dorking via Forest Hill (Class 1 not available). |
| U | South West Trains | West Croydon and Guildford. |
| V | South West Trains | Brighton to Reading/Paignton (one direction only). |
| V | Thames | Gatwick Airport to Reading/Oxford (one direction only). |
| V | Any | Other trains to Great Western Zone destinations (one direction only). |
| W | Thameslink | Bedford and Brighton via Herne Hill. |
| Y | South Central | Charing Cross and Caterham/Tattenham Corner.
Charing Cross and Horsham. |
| Y | South West Trains | Brighton/Littlehampton and Salisbury/London Waterloo via Havant. |
| Y | Railtrack | De-icing Trains. |
| Y | Any | Trains not covered elsewhere. |
| X | Any | Out of Gauge and Exceptional Loads. |
| Z | Railtrack | Sandite Trains. |
| Z | Any | Special Traffic Trains. |
| Beckenham Junction to London Victora (letter H) | Even numbers |
| Stewarts Lane to London Victora (letter T) | Even numbers |
| Empty trains to London Victora | Same last three characters of train number allocated to subsequent service. |
| All other routes to London Victora | Odd numbers |
| London Victoria to Beckenham Junction (letter H) | Odd numbers |
| London Victoria to Stewarts Lane (letter T) | Odd numbers |
| London Victoria to all other routes | Even numbers |
| To London Bridge and Charing Cross | Even numbers |
| Empty trains to London Bridge | Same last three characters of train number allocated to subsequent service. |
| From London Bridge and Charing Cross | Odd numbers |
| South Central services Oxted to Uckfield locals | Even numbers |
| South Central services Uckfield to Oxted locals | Odd numbers |
| South Central services Hastings to Bognor Regis via Littlehampton | Odd numbers |
| South Central services Bognor Regis to Hastings via Littlehampton | Even numbers |
| South Central services Watford to Brighton | Odd numbers |
| South West Trains services to Brighton via Havant | Odd numbers |
| South West Trains services from Brighton via Havant | Even numbers |
| Thames services to Gatwick | Even numbers |
| Thames services from Gatwick | Odd numbers |
| Thameslink services Southbound to Brighton | Odd numbers |
| Thameslink services Northbound from Brighton | Even numbers |
| Thameslink services to Sutton anti-clockwise via Wimbledon | Even numbers |
| Thameslink services to Sutton clockwise via Wimbledon | Odd numbers |
| Other services (Up Trains) | Even numbers |
| Other services (Down Trains) | Odd numbers |