Suggestion from a former loyal Upwork user - DO NOT USE IT. I'd been putting up with their high service fee (20%) charges as I believed that they were a reliable platform - but I was wrong.
Their customer service is TERRIBLE - rude and ignorant. If you did anything "they determined to be wrong" and that you aren't even aware of, next thing you'll find your account being suspended, and you'll receive an accusation email requesting you to write a statement like you have committed a crime.
If you don't follow their "rules", they'll do whatever they want to your account - for example, delete your information, terminate your account - because you are not "behaving".
Oh, forgot to mention their "conversion fee" - 12% of your 12-month earning. Don't know what they invented that for, but be careful as what you have been working hard on could be easily taken just like that. How convenient.