I used Mercury for a side project / startup, and once I wound it down it was impossible to cancel my account. My account was eventually canceled because I refused to respond to KYC more than a year after I had wound down the company and already filed dissolution paper with the state/IRS. I even had my business attorney reach out to them and no action was taken to shut the account. As I had already transferred the majority of funds out during liquidation, I just let it ride. I think I ended up losing $11 or thereabouts. As easy as it was to set up the account and get started, I would never use/trust Mercury again after my experience.