Double Discount Railcard 16-25 and Disabled Railcard

[yorkie]

I don’t think there is anything preventing other retailers selling the fares with the special discount. They just have to bear a loss from doing so and, inevitably, will choose not to.

True but is it lawful to deprive third party retailers of customers by selling at artificially low prices they can't compete with?

(No need to actually answer this as the answer can be found in my quote above!)