Who needs a work permit?

The following categories of people can take up any lawful employment in the UK and do not need a work permit:

Nationals of EEA (European Economic Area) countries (the EEA comprises the 25 EU member states - Austria, Belgium, Czech Republic*, Cyprus, Denmark, Estonia*, Finland, France, Germany, Greece, Hungary*, Ireland, Italy, Latvia*, Lithuania*, Luxembourg, Malta, Netherlands, Poland*, Portugal, Slovakia*, Slovenia*, Spain, Sweden, United Kingdom – and also Norway, Liechtenstein, and Iceland)
Those with Indefinite Leave To Remain in the UK (Permanent Residence)
Those in the UK as the spouse of an EEA national
Those in the UK as the spouse of a work permit holder, Training Permit Holder, Sole Representative, Investor, Student, ancestry visa holder
Commonwealth citizens with ancestry visas (sometimes called patriality) – these visas are available to Commonwealth citizens with a grandparent born in the UK. They should be applied for by the candidate at the British High Commission in their home country. They are usually issued for a period of four years; after four years in the UK the candidate is generally eligible for permanent residence.
Those with pending claims for Asylum in the UK (NB workpermit.com does NOT handle asylum applications)
Those in the UK on a visa as the 'partner' of an EEA national, Work Permit holder, Training Permit Holder Sole Representative, Investor, Student, Ancestry visa holder. These visas are issued in cases where the partners are not legally allowed to marry (for example because they are of the same sex, or because one or both of them are married to someone else) and have been co-habiting for at least two years prior to the visa application
NB Nationals of those countries with a (*) above must apply for a registration certificate under the Worker Registration Scheme within one month of commencing a new job in the UK.

In addition to these categories of people, nationals of European Community Association Agreement countries (Bulgaria and Romania) may come to the UK to set up in business and are exempt from the usual investment requirements.

UK Work Permit Guide

The most important thing to understand in UK work permits is that in the UK the employer applies for the work permit and the the work permit is granted for a particular employee. If you are an individual hoping to work in the UK, you cannot apply for a work permit. If you have a work permit for the UK, you can't change jobs without getting a new work permit.

The following are the most-frequently viewed pages in this section, and may help you find the answers to your questions:

The difference between a Work Permit and a visa
Do I need to get a UK Work Permit?
Obtaining a UK Work Permit
Alternatives to the Work Permit scheme
Work Permit application form

In addition, the following important and useful information:

How long will it take to get an employee on-site with a UK Work Permit?
Information for recruitment companies
Work Permit Duration and extension of the Work Permit
How do I apply for a UK Work Permit
Entering the UK on a Work Permit
What Data and Documents do I need to get a UK Work Permit?
Consequences of illegal employment
Spouses and Dependents of UK Work Permit holders
Employers' Liabilities