Can I go to London on a short-term visit for three months as an au pair?
Basically it is possible to be an au pair for a short stay of only 3 months in London. However, you need to remember the new conditions for au pair stays after Brexit.
In general, the more flexible you are with the conditions of your stay, the simpler and faster it is to find a family. Keep the following points in mind:
1) Don't only look for host families in London. Great Britain is the classic host country and English is the number one global language. Many young people want to go to London. Think about whether you might not also be able to stay in another British city or in a smaller town.
2) Be flexible with the length of your stay and with the beginning and end date of your stay. Instead of entering a definite date in your search criteria, put in a wider time period.
Host families tend to be looking for an au pair for at least six months and most preferably for a full year. Therefore, think whether a stay of six months would be possible. That will increase your chances of finding a family enormously.
Can I be an au pair in the UK as an American?
U.S. citizens are unfortunately not allowed to work as au pairs in Great Britain. As an American, you can enter the United Kingdom with a tourist or student visa. In the first case, you could then live with a family as a guest. But you would not be allowed to work for them. You would also have to leave the country after three months.
With a student visa you could work as an au pair in a host family in Great Britain if you can also document that you are studying in the country. With such an arrangement, you cannot work more than 20 hours per week as an au pair. You should be aware that the costs for the application for a student visa are quite high. You should also consider that the classic au pair idea of travelling to another country in order to learn a new language does not apply when you go to Great Britain since English is already your native language.