When someone who was born and given their name in a country that uses multiple family names lives in the U.S., are there rules as to what their "official" last name must be?
I heard an immigration officer use a first family name as a "last name", which caused confusion, in this case, to the point where the person being called did not realize it was them that was being referred to.
This is because this person has a Portuguese-style name, where a full name like "João Carlos Fernandes Gonçalves Gomes" refers to a person with the given names "João Carlos" and the family names "Fernandes Gonçalves Gomes". Their father's last-in-order family name was most likely "Gomes", and when a short name is called for, they're probably known as "João Gomes". However, in this case, the immigration officer would have asked for a "Mr. Fernandes".
Was this a simple confusion with Spanish-style surnames, where a "Juan Carlos Fernández Gomez" would be most commonly known as "Juan Fernández"? Or is this a general rule in the U.S., that long last names are always shortened by choosing the first part of it?
Can poor João write his name on official documents as "João C. Gomes" (or another choice of middle initial) without applying for a name change, or is that strictly incorrect in the U.S.? He had thought it'd be simple when he heard the terms "first name" and "last name"—"João" is literally the first, and "Gomes" the last, in order, in his full name.