The question of whether you will need a visa to enter the United Kingdom will depend upon your nationality. To best answer if this is going to affect you it is necessary to break this answer down into three applicable sections:
Citizens of the European Union
When the United Kingdom joined the European Union back in 1973, it automatically assumed the responsibility of having to permit other members of the union to enter its borders. This is a very strict law that is set out in primary legislation and although there have been some minor derogations in the past, the UK has a responsibility to abide by this. This has extended to the countries that have become the newest members of the EU (mainly from the former European Eastern Block countries). In turn, this has led to a tremendous influx of legal immigrants from countries such as Poland, The Czech Republic, Hungary etc and this has swelled the country’s population by literally millions of people.
Under EC law, members of the European Union have an automatic right to enter the UK without a visa for a period of six months. Providing they can prove that they are actively seeking employment, they can even claim ‘Job Seekers Allowance’ for this time. If the EU citizen is not able to find work within this time and cannot prove that they are not going to be reliant upon the state, they will no longer be permitted to remain within the country.
For non EU citizens things become a little different. Group 1 relates to the countries that the UK Government do not construe as posing any potential threat to the nation. For countries that fall within this categorisation, they will not need an actual visa to gain entry into the country but will probably require a type of visa waiver. Some examples of the countries that fall within this list are the United States of America, Australia, Canada and New Zealand.
Non EU Countries (Group 2)
There is an extensive list of countries that come under this category and before you even attempt to enter the United Kingdom, you must approach either a British Embassy of High Commission (for countries that are in the Commonwealth), to ascertain whether or not you will require a visa. If the answer is yes, you will need to sort out the visa before you travel and these will vary depending on the purpose of your trip to the country.
The basic type of visa will cover a stay of up to two months and this would not permit you to seek or undertake any work in the UK. Visas then go on to cover academic studies in the country and even permits to work. The costs for the visas will depend on the type being sought: anything from £68.00 to many hundreds of pounds for extensive stays in the country.
Visas and the security of the United Kingdom are all controlled through The UK Border Agency and this is a branch of the UK Home Office.