Workplace Communication

Yes - a short, warm birthday note is almost always welcome at work. Keep it professional: one or two sentences, no inside jokes unless you know the person well, and no comments on age.

Only the ones you already share openly at work. A reference to a shared project or a quality you admire in them as a colleague works well. Save anything more personal for people you know outside the office.

Slightly more formal than to a peer, but still human. Thank them for something specific (mentorship, a decision, a piece of advice) and keep it brief. Avoid flattery - it reads as transactional.

If they have posted about their own birthday or your company has a culture of public recognition, yes. Otherwise, a private message or a team chat is usually a better fit - not everyone wants their birthday broadcast.