In most cases, you will use the Dartford Crossing on your way to the UK. When going clockwise, you will use the bridge; the tunnel serves the opposite direction under the river Themse
The charge for using the crossing is 3 pounds; you can cross for free from 10 p.m. to 6 a.m. The charge is payable by midnight on the following day. Non-payers pay a penalty of up to 120 Pounds. You can pay the charge online on the following website:
dartford-crossing-charge

Self pay system is not possible to set for vehicle registered  outside UK

The history of the tunnel

The history of the bridge

Traffic cameras

Step-by-step instructions for paying the charge for crossing

1.Starting page of charge page
2. Click for one off payment
3a. Add your van into system
3B. ad info about your van
4. Pay with your card