This is a list of useful codes for the Avantix Traveller "National Fares Information CD" (now available as a download, free account required, from here, the Brfares online manual, and a dwindling number of online journey planner sites.

eg https://trainscanbecheaper.info

1) For an "Out-boundary Travelcard" - that is, a travelcard whose origin is outside the London Zones, use destination
   code 0035

2) For a single-trip ticket to an Underground destination further than the London terminal, use codes:

(Note that in 2022/23 not all of the below may have a price, depending on the origin station, and few - if any - online booking
 sites now issue tickets to these codes)

0785 Underground Zone 1
0790 Underground Zone 12    0793 Underground Zone 2
0791 Underground Zone 123   0797 Underground Zone 23    0830 Underground Zone 3
0792 Underground Zone 1234  0825 Underground Zone 234   0835 Underground Zone 34
0065 Underground Zone 1245  0066 Underground Zone 2345  0067 Underground Zone 345
0786 Underground Zone 1256  0829 Underground Zone 2356  0839 Underground Zone 3456

0841 Underground Zone 4     0069 Underground Zone 5     0070 Underground Zone 6
0068 Underground Zone 45    0847 Underground Zone 56
0844 Underground Zone 456

(At the time of writing v1.0 of this guide, in around 2010, I had not seen any prices at all, for the six immediately above)

3) For a single-trip starting from the London Boundary Zone, use codes:

0041 BZ2    0043 BZ4    0072 BZ6
0042 BZ3    0044 BZ5

(Not all of the above may have a price, depending on the destination station).

4) For tickets to/from St Pancras on HS1 (the so-called 'southeastern highspeed' service), use code 1072

5) For walk-up tickets to Thameslink stations in the centre of London, where available don't use "London Terminals"
   Instead use London Thameslink code 4452.

   nb. These tickets are to Farringdon, City Thameslink, London Blackfriars, London Bridge, Elephant & Castle.

6) For National Rail tickets to Heathrow, use code H584. These are valid to all three stations, via the free inter-terminal
   rail service

7) For CIV tickets [some with unrestricted peak-time travel, and with guaranteed onward connections to Eurostar]
   to/from London St Pancras use code 5470


The following have not been individually checked for acceptance of Avantix codes:

Online ticket vendors, Great British Rail Sale April 2022

Avanti West Coast
C2C
Chiltern Railways
CrossCountry
East Midlands Railway
Grand Central
Greater Anglia
Great Northern
Great Western Railway
Hull Trains
LNER
My Train Ticket
Northern
Omio
RailEasy
Railsmartr
Redspottedhanky
South Western Railway
Southeastern
Southeastern High Speed
Southern
Thameslink
thetrainline.com
Trainhugger
TrainPal
Traintickets
TransPennine Express
Trip
West Midlands Railway

Additional online ticket sites

Caledonian Sleeper
Eurostar
Gatwick Express
Happy Rail
Heathrow Express
Island Line
London Overground/Underground/TfL Rail
Lumo
Merseyrail
Scotrail
Split My Fare
Split Ticketing
Split Your Ticket
Stansted Express
Strathclyde Partnership for Transport
Ticketysplit
Trains Can Be Cheaper
Trainsplit
Transport for Greater Manchester
Transport for Wales
Travel South Yorkshire (Zoom)
Tyne and Wear Metro (Nexus)
West Midlands Centro/Network

Last updated June 2022