A visa is a document issued by a country giving an individual permission to formally request entrance to the country during a given period of time and for certain purposes: like tourism, study, work etc. Whether you need a visa depends on the purpose and length of your stay and on your nationality.
Citizens of the member countries of the European Economic Area (EEA) and Swiss nationals have free access to enter the UK to work and study. However, if you are a national of a country that has recently joined the EEA, you may need to register or apply for permission before
you begin work . Other nationalities need a visa to remain in the UK for work or studies.
People living and working in the UK for five continuous years (two, if spouse or partner of a British citizen) may be eligible for Indefinite Leave to Remain (or Permanent Residence). You need to contact the UK Border Agency to understand your rights and apply for this visa.
After 12-months of holding an Indefinite Leave to Remain visa, you may apply for British citizenship. Children born in the UK with one parent who is (or becomes after birth) settled in the UK or a British citizen can also become a British citizen.
National Insurance Number
Why and how to obtain your NI number.
More information