Stockholm has a congestion pricing system, Stockholm congestion tax, in use on a permanent basis since 1 August 2007, after having had a seven-month trial period in the first half of 2006. The City Centre is within the congestion tax zone. All the entrances and exits of this area have unmanned control points operating with automatic number plate recognition. All vehicles entering or exiting the congestion tax affected area, with a few exceptions, have to pay 10–20 SEK (1.09–2.18 EUR, 1.49–2.98 USD) depending on the time of day between 06:30 and 18:29. The maximum tax amount per vehicle per day is 60 SEK (6.53 EUR, ). Payment is done by various means within 14 days after one has passed one of the control points; one cannot pay at the control points.