Hi my three children are all going up to London today for the first time on their own. Last night we topped up our oyster cards for them but are confused as it said the top up wont be activated until they use it at the nominated starting station for their journey. Only worried as they now are saying they may meet friends and go from a different station. I would have thought if you top up online the money would automatically go on from which ever station you go to? Confused !