tubechallenge.com

I seem to have 672. Are you missing:

Broxbourne, Brentwood, Shenfield, Ockendon, Chafford Hundred, Grays and Purfleet? These stations are not within TfL zones (like Watford Junction), but are possible on Oyster PAYG.

These 672 are split into:
- 270 tube stations
- 41 DLR stations not linked to the tube
- 38 Tramlink stations not linked to the tube (or DLR, but none are anyway)
- 323 National Rail stations (including London Overground) not linked to the tube, DLR or Tramlink

If they are not in the zones. It would be a very unlikely twist that would need them included. And involve extra expense for the challenge.

Hey, Stratford International (NR) is in that bag! And so are the Heathrow NR Stations (though admittedly they can be visited for free).