travel from Heathrow to Cardiff

Hi, This question was answered, but back in 2010, so I am just trying to confirm the answers are still the most current/best. I'm flying into Heathrow, arriving at 7:05am and am considering travel to Cardiff for the day or possibly overnight to visit a friend. I need to be back in London for a conference the following week. Is my best option to catch a coach bus (length of travel is first priority since it'd be such a short trip, then cost) or a train? From what I've read, I need to transfer to the Reading station to then catch a coach? Is there anything directly from Heathrow? Probably more importantly, if I'm to come back later that day or the next day - when I'm likely to be pretty tired - I'd like an easy trip from Cardiff to London (Westminster tube station is where I need to end up). Any suggestions or tips are welcome. Thank you!
Lisa

Posted by Tim
Minneapolis, MN, USA
8640 posts

You can take a National Express coach (highway bus) directly from Heathrow to Cardiff. Coaches you could catch leave from the Heathrow central bus station at 09:05, 10:10, and 11:05. The trip takes a little over three hours. Direct trains from Cardiff Central to London Paddington make the trip in a little over two hours. The standard 2nd class fare is quite expensive. However, if you book ASAP (up to about 12 weeks in advance) at eastcoast.co.uk, you can get a discount fare ticket as low as £12.00. Those tickets are for a specific departure date and time and are non-exchangeable and non-refundable.