dog on train

[DominiqueBernard]

I don't live in U.K. I need to book a train from Leeds to London for my adult sister, me, and my sister's dog. The dog is a Dachshund, so not very big. Are there any rules around dogs on this type of train? Do I need to book a place for the dog / state that there is a dog when booking (I can't see these options online) ?

Nope. Just turn up and go.

Not as far as I know, I've taken my Bedlington to London and back several times

You can generally take dogs on trains (free) - up to 2 per adult, and they must be on a lead or in a carrier at all times

I hope the dog is properly housetrained, and can easily manage the proposed length of journey without needing to go.

Thank you, the dog takes the train often with my sister and has a carrier, is trained, etc., but I am booking these tickets as my sister is caught up with a work thing so I don't want to bother her.

Just bring it along, and be a good owner and keep it out of everyone's way.