Well. I don't know what you try to do, so it's some hard to answer compleete, but
there are a lot of places where you can check if it's registered, because a registration need to be done in 15-20 places (although in some regions they have put some of them together.) I don't know which information is accessable for others though. Here are some examples:
/If having employed long time enough: SSS, PhilHealth, Pag-Ibig for each employed.
/At least if it's a baranggay in province (=a baranggay with not big amount of companies) I would START with asking there.
IF there are no company registered, then there is no "legal business unit", then I suppouse no person can sign contracts in that business name LEGALY. If so YOU don't need to break the contract, because the other has allready "broken" it by signing it illegaly.
But it's rather common with not proper registered small businesses in the Philippines, so I DON'T know what's practice in such situations.