This is one of the nuances of usted that I still haven't quite figured out. At my retail job, I often assist Spanish-speaking customers. However, I am not sure if these situations warrant using more formal language. In English, I address my customers politely with "Sir" or "Ma'am" but the language I use otherwise as I'm assisting them is more informal. I want to maintain the same tone of politeness yet casualness in Spanish as English but I don't know if it comes across as too formal. For context, I am in my early twenties and the customers I've spoken to are almost always older than me ranging from their thirties to more elderly people. Obviously, for my older customers, I would use usted but would it be necessary to use usted for people who are not that much older than me? I don't know if there is anybody here who can shed some light on this topic. In Spanish-speaking countries do retail employees typically address their customers with more formal, usted language?