Basically there is a system for managing migration for those wishing to enter the UK for work or study – The Points-Based System (PBS) 

Tier 1 (General) Migrant of the Points Based System was launched for foreign nationals living in the UK on 29 February 2008 and replaced the Highly Skilled Migrant Programme (HSMP). On 30 June 2008 three additional sub-tiers were rolled-out and the programme was extended to include applicants resident overseas. The four sub-tiers are Tier 1 (General) Migrant, Tier 1 (Investor), Tier 1 (Entrepreneur) and Tier 1 (Post-Study Work). Tier 2 for Skilled Workers and Tier 5 for Temporary Workers and the Youth Mobility Scheme were launched worldwide on 27 November 2008. The first stage of Tier 4 (General) Student and Tier 4 (Child) Student rolled-out on 31 March 2009. Before you proceed any further know your visa better.

Points Based System Tier 1, General Migrant (INF 21)

This guidance is for applicants who are resident outside the United Kingdom. It explains what to do if you are a highly skilled person wishing to seek work or self employment in the United Kingdom (UK) under Tier 1 (General) Migrant of the Points Based System.  It is only a guide but it aims to answer some common questions. There are also notes to help you to complete an application form.  More comprehensive guidance is available on the UK Border Agency website, which is the definitive version, and in the event of any discrepancy overrules the information provided herewith. You should also consult the UK Border Agency guidance if you are resident in the UK.

Remember

To qualify for Tier 1 (General) of the Points Based System you must be able to demonstrate that you have funds to support yourself and any dependants. For the main applicant this is £2,800 with a further £1,600 needed for each dependant accompanying you or planning to join you within 12 months of your arrival in the UK.  These amounts must be held in your personal bank account for a minimum period of 3 months for which you must show bank statements/other evidence immediately preceding and dated no more than 1 month prior to the date you submit your application. The balance should not fall below the required minimum at any time during the 3 month period. Remember to visit the list of countries from where visa is mandatory to visit the UK.

Visa fees

All fees are in pounds sterling, but are usually payable in local currency. Please contact your nearest visa application centre to find out what the local fees are and how you can pay for your visa.

Dependants are charged the same fee as the main applicant. All dependants who are travelling must pay the fee whether or not they are included in the main applicant's passport. Fees are subject to periodic review. Visa fees are non-refundable but if a payment has been made and the application is not submitted or if the applicant refuses to provide biometrics details with their application, then refund of the fee is made.