Is it tax fraud or just unethical?

What is your goal? If you are CFO of the company you may have a different goal that if you are a janitor there. You say "these are all being claimed as company expenses and not as personal income, avoiding paying taxes" and then have a heading "Tax fraud or unethical?"

If you are aware of something, rather than post it online get an attorney involved. If you are going to be a whistleblower, blow the whistle rather than just posting things that are hypothetical. Beware what you asked for, however. It may come true.

Check with a lawyer in your locale to discuss more of the details.

Good luck to you.

God bless.

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It really depends on the circumstances - but you have good reason to be alarmed as the feds take a dim view of this sort of thing. Talk to an attorney in confidence about this and keep your silence otherwise.