I will be traveling with a 10-year-old and I wonder what is the best way to go to Heathrow from Westminster or Piccadilly area late in the afternoon on Sunday (August 1)?
Please help

the Piccadilly line goes to all Heathrow terminals - whether that is best for your criteria or not is different but by Tube it's a straight shot from Piccadilly

From Westminster take the District Line westwards to Hammersmith, walk 10' to the adjacent platform and get a Piccally Line Tube to Heathrow.

Note that not all Piccadilly Line Tube services go to Heathrow and the one's that do serve Terminals 1,3,4 or 1,3,5. So if you are going to T4 or T5 there's a 2nd check to do.

It depends where <u>exactly</u> where you are starting from. Piccadilly and Westminster would be different (and other stations might be closer)

From Piccadilly would be one route (Piccadilly line). From Westminster you'd want to follow alanRow's advice.

So where will you actually be?

I would recommend the tube as well but be aware that it will probably be crowded and you may have to stand - at least initially until someone gets off. If you have heavy luggage, just put it to the side once inside the door, out of the way of people getting on and off.

The other options are taxi, Heathrow Express from Paddington, Heathrow Connect from Paddington or a car service. A lot of people recommend Just Airports, you can check prices on their website if you don't like the idea of a crowded tube. The tube is your cheapest option, taxi is the most expensive.

Kay

How expensive would be Taxi? Concerned with 2 suitcases and a kid on Tube.

Your hotel can book you a minicab (private taxi) and it will cost you around 40-50 quid from Westminster. A black cab will be more, most likely upwards of 70 quid. Definitely arrange a private taxi.

Use www.justairports.com instead of a hotel booked mini cab. You do have to book it in advance -- not just call them at the last minute.

Will run approx £30-ish depend on the exact postal code.

<<< be aware that it will probably be crowded >>>

Not on a Sunday

All your help is much appreciated.