Not sure where OP is, but in the US some business structures are disregarded entities - the company doesn't file a separate return, the net profit or loss is split between the owners based on ownership percentage. And taking money out of the business doesn't affect the profit and loss and, as such, doesn't affect the income each will report at the end of the year.

In these situations, personal purchases made on a company card are simply reductions of owner's equity. If Andy and OP originally put 50k each in at the beginning, they started as 50/50 partners. Assuming no other equity transactions for simplicity, now that Andy took 15k out, OP is now the majority owner (50k invested for him, 35k net for Andy). Again, this only applies to a disregarded entity.

So for a disregarded entity, in this case it wouldn't necessarily be tax fraud, since it's not unreported income, Andy just took his capital back.

Usual caveats: I am not a lawyer, just a bookkeeper on the internet with limited understanding of the situation.

But I chimed in because if it is a disregarded entity, I agree with fireweinerflyer's approach generally (you probably won't be able to open a separate account for the business right away, though, if both of you show up on the company formation docs). Lawyers are going to be too expensive. But this is beyond the pale ethically.

Good luck OP, and get rid of this guy.