London questions

With a family of five, a black cab probably is the cheapest.

You need verification of this, but last time we were there we were told the daily tube ticket also covered busses 9and the train to Hampton Court). Depending on how much Tube you intend to do. Weekly or Oyster cards may work better for you. Tons of places are walkable Taxis are great , but susceptible to being caught in traffic- or difficult to find at some times

We were a group of 4 staying near London (Kew Gardens vicinity) last summer for 2 weeks and traveling into London about every other day. We had 3 adults and one child who was 8. How old are your children? We too debated about what type of card/ticket to buy since we started our journey by train in zone 1-2. Ultimately we went to our ticket window person on day 1 and asked her recommendation for the least expensive scheme telling her about how often we'd be traveling. She recommended putting money on Oyster cards for the adults and traveling at off peak times and paying a 2 pound fee each day for a child's paper ticket. Once we were in London we rarely used the Tube again. We mostly walked and used the buses which were included on the daily maximum cap (~7 pounds for each adult and the 2 pound children's ticket). Since we were house exchanging we had use of the family's Oyster cards. We did not need to buy new cards which have a refundable deposit. We didn't buy an attraction type card as most museums are free. If you plan to go to some high cost attractions though such as the London Eye, Tower of London, etc., it might be worthwhile to investigate this. It depends on what you want to see.

Hampton Court is in the same zone with Heathrow, zone 6.

Just buy a day pass for each of you and take the tube. Cheaper than taking a black cab everywhere.

It's important so I'll repeat Mona's question. What are the ages of your children?

The kids are 15 years old. Thanks
Krista