Contractors in the UK are required to have a valid UK work permit, so if you are coming over to the UK it is important you have obtained one.
The exception to this is individuals who are coming from other European Union member countries as one of the key concepts of the EU is the ability for citizens of member states to freely live and work in each others nations.
Individuals arriving from outside of the EU are required to obtain a work permit from the British border office. Some countries who joined the EU in 2005 or 2007 may also be required to apply to work in the UK so if you are unsure if this applies to you, a simple google search will clarify what countries joined in those two years.
Work Permits
Work permits are the most common way to enter a country with a view to work, whether that be the UK or abroad. Different countries have different requirements for granting work permits (or whatever the equivalent name may be for example in the United States it’s called a H1B Visa).
Granting a contractor a work permit can often depend on a series of factors such as the skills you have gained in your profession, providing of acceptable forms of identification (usually including a passport), the possibility of a job with an employer from that particular country and in some countries even the ability to prove you can fit into the culture and speak the language. For example, if you are looking to move to a country full-time, they may make you pass a test to prove you capable of speaking the language.
Applying for a Visa
Most countries will openly provide information to contractors considering moving abroad to work whether temporary or indefinitely, but the actual process of applying will differ from country to country.
Luckily the growth of the internet has provided a plentiful resource for potential immigrants looking for more information – both from the authorised government agencies who provide the documentation and process the applications but also from other individuals who have been in your position before who are willing to share their experiences to help others.