The same way any company performs anti-fraud checks.

And how this is done - check the provided information against a known-good database (there are plenty of services that you can pay for here). Perform random spot checks. Make sure that the UBO is filing taxes for this entity’s earnings. Etc.

I’m not claiming it’s perfect; fraud detection is a hard problem, and it’s also pretty obscure if you haven’t had to deal with it at your own company.