Here is the situation:
I have a meeting scheduled with a client/stakeholder/co-worker at 12pm, and I arrive at 11:50am and order myself a drink before they arrive. They end up arriving at a reasonably prompt time (12pm - 12:05pm) and I have already 80% finished my drink.
Is this considered rude?
[Experience: US consulting and academia]
In general I would say no, but it depends a little on the context.
Having a (mostly) empty drink in front of you can highlight the fact that you arrived first and indicate how early you arrived. If this is a situation where it would be embarrassing for you to have arrived significantly before the other person, don't do it (also, in such circumstances, don't arrive early).
If the meeting is specifically to get drinks, then it could be considered rude by some people. This is similar to how it's rude to begin eating before everyone is seated at a table. If it's a meeting that happens to be at a bar and there's no expectation of drinking as a group activity, I would think it wouldn't be considered rude.
I would avoid having more than one glass in front of you though. That can give off the impression that you've been waiting for a long time which can embarrass the person who has made you wait, even if they aren't officially "late".
Is this considered rude?
That is dependent on the individual, but in general it's not rude. But I normally apologise with some empty platitude such as
"Sorry, I arrived really early so I've already ordered myself something. What would you like?"
If they've arrived in a reasonable time, then excuse it as your fault for arriving early.
Here in Finland everybody drinks kahvi (Finnish for coffee) many times a day and it is considered normal. It is never considered rude to drink coffee before, during, or after a meeting.
Most programmers only survive with the power of kahvi, so if there were no coffee during a meeting there would be no work done!
Therefore don't worry, be happy, and enjoy many kahvi!
Very rude, at least in our culture (Europe). If the meeting is at e.g. 6 pm there is no point in arriving early and enjoying the place without the other person nor in not waiting for the other person to arrive.
Do not do this, going thru the menu together, waiting in line etc etc is a good causal moment to spend together, no point in eliminating it to get you coffee 5 minutes early.
If this is your client, and you invited them to a meeting at a place like Starbucks, yes. If this is a nice sit down place where the waitress brings you your drinks, and food with the bill at the end it is much less of a deal.
The standard expectation is that you will wait for them and cover tab. Also it conveys an image that you may have chosen to come there for the drinks rather than the meeting. Since this is your client your best impression is made by waiting for them to get anything. I would say the exception to this would be water. If you arrive and need a drink get a glass of water, then order your preferred drink when they arrive.
How bad of a faux pas it is depends on your current relationship with the client. If this is just a standard update meeting that happens every week or 2, then its not really a big deal. If your client is not happy and you are struggling to retain their business this could be one of those things that tips them over the edge. If this is a new client it is not something I would risk as different people have different ideas on what is proper and what is acceptable. You only have one chance to make a first impression, I would not want it to be that I value the drink more than my new client.
It depends on the setting of the meeting. Since you said ordered a drink, I assume it is a neutral setting like a restaurant or a cafe. If it were at your company or home, it would be rude if you did not offer them the same. Otherwise, I don't see it as rude. I am from the US for the record.
