Documents, entry requirements & customs (visas, etc)
Detailed information on visitor visas and other entry requirements can be found on the website of UK Border Agency.
Full details and information on customs allowances can be found on the website of HM Revenue & Customs:
Money and currency
The pound sterling (symbol: £) is the official currency of the United Kingdom.
Health and travel insurances
A good travel and health insurance in case of any accidents or sickness during the stay in the United Kingdom, in particular, in London is required.
European Health Insurance Card (EHIC): It enables holders to access medical resources when travelling outside of their EU country of residence.
More information can be found on the website of the National Health Service.