Not long ago, the London authorities decided to take money from citizens, digging with or without a detector in the mud on the banks of the river Thames. This “activity” is also popularly called «mudlarking».
Now the cost of this “attraction” is 32 pounds per day. But they also made a special discount for citizens of London – 75 pounds for three years of digging!
The logic behind this is clear. If you are a tourist, then you pay 32 pounds and you can dig all day.
Besides this, there are strict regulations for where you can dig, and where not, and where to call in case of a treasure or an archaeological find.
To obtain a permission you will need to submit an application on two pages with a picture of yourself +payment. A completed application form with a photo can be sent by mail or e-mail. All information in English about this can be found on the website of the London port (here).
The processing time of the application is at least three weeks.