Interns are also occasionally told that they are self-employed. It is important to note that your employer cannot deprive you of your employment rights simply by labelling you as self-employed. What matters is the real nature of your relationship with the organisation providing your internship and, for example, whether that organisation tells you what work to do and when to do it.
There is more information available on determining your employment status is you are an intern.
Under National Minimum Wage (NMW) law, employers are required to prove that an individual is self-employed and therefore is not entitled to the NMW. You are presumed to have a right to the NMW unless your employer can show that you are running your own independent business or you are not required personally to do the work set by the employer, but could instead use a substitute.
As an 'intern', it is highly unlikely that you will be self-employed. If the employer tells you what work you must do or provides you with training, you are probably meet the definition of a 'worker' or an 'employee' and will have the right to be paid at least the NMW and enjoy other employment rights accordingly.
HMRC inspectors have powers to investigate and fine employers who fail to pay the NMW to workers by incorrectly labelling them as interns. HMRC can also recover wage arrears on your behalf. You can report your employer for non-payment by contacting the Acas Helpline. With your consent, a helpline adviser can refer your complaint to the HMRC National Minimum Wage enforcement team.
HMRC can also 'name and shame' organisations that fail to pay the National Minimum Wage in a public list.