"Complex ownership structures, international money flows and complicated business models pose higher risks in terms of fraud and money laundering. It can take customers from weeks to months to open an account due to ineffective due diligence. Transactions and accounts are often frozen as a preventive measure until they have been manually checked by experts."

https://www.finextra.com/newsarticle/41577/penta-co-founder-raises-3-million-for-swiss-banking-startup