Can au pair become a nanny?
It depends what you mean by “nanny”. Usually, it’s pretty much the same as au pair. To be covered by the au pair visa, the visa holder must live with the family they are working for. Au pairs are allowed to change to another family as long as the conditions continue to meet the immigration rules. Assuming this is the case, no-one is breaking any law, and the contract would be enforceable in the normal way. Abuse of au pairs has been a problem, if anything like this is occurring, the person concerned should contact someone, for example their own embassy, any reputable au pair agency, citizens advice bureau. Au pairs must be paid and decently lodged, not be given unreasonable duties, have time off, etc. Employers are not allowed to keep passports. Central to the notion of au pair visas is that the primary purpose is to help the au pair learn/improve their English. It is not supposed to be a form of slavery!