How much would a regular taxi be from Belgravia

to Heathrow? Will we hit alot of London traffic? We have a Thurs. 8 p.m. flight.

If you go by 4 pm, to miss the peak hour traffic, I think a proper "black cab" (a licensed taxi) should cost in the general region of £50 on the meter and take about 45 minutes. Don't leave it much later than that - by 5 pm traffic will be very busy.

Your hotel may try to persuade you to take some other form of transfer, almost certainly some "minicab" (private hire vehicle) company which they have an arrangement with. While all minicabs in London now have to be licensed as such, and although some minicab companies operate very nice vehicles, you will want to make sure you know exactly how much it's going to cost you if you do this; as always, the hotel will be taking a significant commission for arranging this.

We will be using http://www.justairports.com in July. We will be going from Buckingham Palace Rd to Heathrow and was quoted 28GBP cash.