As soon as you start work you need to register with the authorities. The Home Office is the name of the government department that registers workers from new EU member states. You can register by going to the Working In The UK website.
http://www.bia.homeoffice.gov.uk/You also need a National Insurance number in order to work legally. You will need to get this when you have got a job.
National insurance is scheme in which employees make contributions from earnings (separate from and additional to income tax) to a national fund from which benefits are provided in certain events, such as, unemployment, sickness or other incapacity, maternity, and retirement.
Every worker in the UK has a National Insurance number, and you need a National Insurance number in order to work legally. It is used to keep track of social security contributions. If you earn more than about £80 a week, then both you and your employer have to pay what are called National Insurance contributions. These are a kind of tax. In return workers gain entitlements to various social security benefits. Paying national insurance contributions in the UK can also help you build up entitlements in your home country.
To get a National Insurance number, you need to make an appointment for an “evidence of identity” interview at the nearest Job Centre. This is a government office that can be found in most large towns or city districts. You will need to take proof of your identity (such as a passport) as well as evidence that you are working. More details can be found on the Department of Work and Pensions website.
You may be given a temporary National Insurance number until the proper number is issued.
You will also have to pay income tax. The amount of tax you have to pay depends on a number of different factors. Every worker in the UK has a tax code, which an employer uses to work out how much tax they should pay on your behalf. If you are starting your first job in the UK you will probably start to pay “emergency tax” until you have been given a tax code.
Some employers may offer you a job without paying National Insurance or tax (known as “cash in hand”). This is against the law. If they are breaking this law, it is very likely they will break other employment laws as well, especially those that protect workers. It will be very hard for you to enforce any of your legal rights if you are not working legally. You should avoid this type of job.
Note that your employer does not need to keep your passport or identity documents, and has no right to hold them. They may make copies of them for their records.
