There are various tiers of worker, from highly skilled to temporary staff, and the kinds of immigration background checks which need to be carried out depend largely on which country the prospective employee is from. Immigration checks are also set to become tighter since the Coalition government announced proposals to limit numbers of migrant workers.
It is a criminal offence to knowingly hire someone who doesn't have immigration permission to perform their role. And, of course, one of the reasons the law surrounding passport checks and immigration background checks is so tight is to protect potentially vulnerable employees who could otherwise be exploited.
Remember, it is your legal duty as an employee to carry out the necessary right to work checks to ensure that someone is who they say they are, and is genuinely entitled to work in the United Kingdom. This usually means firstly doing passport checks by verifying the passport number of all your overseas employees.
