First, from a tax standpoint, both a nanny and an au pair are considered household employees by the IRS even though they are still accepted as being in the child care industry. One difference between them is that an au pair often comes from another country and is part of a cultural exchange. They learn the culture and language in exchange for helping with the homeowner’s children and in some cases light housework. Another difference is that nannies are also usually professionally trained and are a little older with more experience. An au pair is not professionally trained and are typically younger in age.