What is "congestion tax" in London?

It's the Congestion Charge.

It is payable by any vehicle entering the zone (crossing over a big C in the road) between the operating hours. The license plate of every vehicle is recorded by a camera which checks it against the database of people who have paid. If you haven't paid, the address where the vehicle is registered will be sent a fine. It currently costs £8 to enter the zone.

For more info see:

http://www.tfl.gov.uk/roadusers/congestioncharging...

This is not a tax.

This is a charge levied on road users for the facilities (road) that they are utilising.

The boundary is clearly marked, and basically covers the area of inner London circled by a ring road.

As a London resident I think that the congestion charge has worked incredibly well, reducing the congestion on London roads. It has made an enourmous improvement in the air quality and noise level in the area in which i live. The funds gathered by the charge have also improved the public transport system, especially the buses, allowing people who do not wish to pay this charge far more transport options within the City.

See the TFL website for details and to pay if necessary.

It's the Congestion charge, not the congestion tax. Most vehicles entering the area within certain times need to pay it either the same day or the next day. You are subject to a fine if you do not pay it. Buses, coaches and taxis are exempt as are electric cars and cars with a disabled badge (blue badge). There are other exemptions.

The charge can be paid at a number of locations and you can only be charged once a day even if you leave the area and re-enter.

Glad you mentioned the word 'tax'. However, here in London it is called simply the Congestion Charge. This is a charge levied on all vehicles entering the Congestion Charge Zone(s) Monday to Friday.

http://www.tfl.gov.uk/roadusers/congestioncharging...

The reason I'm pleased that you mentioned the word 'tax' in your question, is because that is exactly what it is, a tax. The American Ambassador refuses point blank to pay this 'tax' and I entirely agree with him. Diplomats do not pay tax here in London.

and so it goes. . .