I bought a £10 Network Railcard via O2 this week and I'm so confused as to whether I can use it on the tubes and buses. I know I can't add it to my Contactless, but I found an old first-gen Oyster card.
A very unhelpful (as usual) staff member at Hillingdon yesterday told me it's for rail only, but the TfL website says you can use it on tubes and buses as long as it's Oyster.
Anyone know what's possible and what I should be asking? I'm not surprised it is dependent on getting the right person to add it though.
I am at Euston next week so might try my luck there.
In short, it's complicated.
An Oyster card can be used to PAYG on all rail, Tube, DLR and tram services in the London Zones, and at a few stations beyond the zones on specific routes. It can also be used on all TfL buses (whether inside the Zones or not).
A Network Railcard can't be applied to an Oyster card. This is predominantly because it has a minimum fare of £13 on weekdays, and of course most Oyster PAYG fares are far less than this. Some of the caps are above £13 but you still don't get any discount on these.
You can use your Network Railcard to buy discounted paper/smartcard Day Travelcards after 10am on weekdays, but in most cases these tend to cost more than the equivalent Oyster cap. There are some exceptions, of course - notably on weekends, where neither the £13 minimum fare nor the 10am restriction applies.
If you want to get a discount on Oyster PAYG travel, you can buy a season ticket that qualifies for an Annual Gold Card (the cheapest one is around £200/year) and apply the Gold Card to your Oyster card. You will then get a 1/3 discount on off-peak PAYG rail fares (whether Tube/DLR or National Rail) and off-peak daily caps (which buses count towards, even though the individual bus fares aren't discounted by a Railcard).
The Network Railcard can also be used to buy discounted PlusBus tickets for towns/cities outside of London.