Do I need a birth certificate to travel with a child listed in a parent's passport (old-style passport, no separate child passport)?

If the child travels with an aunt or uncle (not a parent), officials usually require proof that the accompanying adult is actually the child's parent.

When traveling with the father, a birth certificate is almost never requested — matching surname and patronymic is enough. With the mother it's trickier since the patronymic isn't listed on documents, so checks tend to be stricter.

This rule about matching surnames and rarely needing a birth certificate applies specifically when the child has no separate passport and is listed in a parent's old-style (5-year validity) passport.