If you own a car, you will be aware of the Ultra Low Emission Zone, a measure to reduce air pollution in central London by charging daily for driving a polluting vehicle inside the zone.
Before it was only within the Congestion Charging Zone (so only Holborn was inside the zone), but now it has been expanded out to the North Circular and the South Circular, including the whole of the Borough. So if you have an older car, you may need to start paying the new charge.
For more information, see the TfL website:
To check to see if your car is exempt: