I am traveling to London in August 2018 with my wife and 2 kids aged 11 & 8 years respectively. I need some clarity on the Oyster Card
1) For a family of 4, do I need to buy separate oyster cards for each family member or just one card is sufficient and I add money for 4 people to travel
2) Do kids go free or have a discounted rate on the oyster card
3) How do I activate the daily cap.