Horton, I don’t know where you got your information, but you’ve been sadly, woefully misinformed. I’ve been paying tithing since 1996, and I’ve never shown a bishop a tax document, or been asked for one. I’ve lived in five different areas in two states in that time, and met with probably ten or more bishops.
I’ve heard the notion that I “must” meet every year several times from critics of my faith. I’ve never been told I “must” meet by any church member or church leader.
The ‘meet with their bishops once a year’ thing is called Tithing Settlement, and yes, it happens. The bishop asks a question: “Are you a full tithe payer?” You answer yes, no, or part-tithe payer. He checks a little box. When folks ask what constitutes a full tithing, the bishop brings out the scriptures, and doesn’t advocate for gross or net. He doesn’t ask for proof.
Yes, to have an active temple recommend, and LDS member must be current on tithing. That part is true.
The OP’s question: “Which religions require 10% giving or some specific minimum?” Nobody will kick you out of my church for not paying tithing. It’s heavily recommended, we teach about it, we ask about it, you can’t enter the temple without it, but no, it’s not required to be a member.