Castle combines operating cash, high-yield reserves, and bitcoin management in one platform, with automation for recurring purchases and transfers. Its official materials describe account integrations with payment and accounting systems such as Stripe, Square, PayPal, and QuickBooks.
For businesses, Castle presents liquid access, account allocation controls, and third-party custody as parts of its treasury workflow. Its personal-account materials extend cash, yield, and bitcoin features to individual savers, allowing the company to serve more than one customer segment through a shared account platform.
Castle's products operate in financial markets that carry counterparty, custody, liquidity, and volatility considerations. The company states in its terms that it is not a bank, broker-dealer, money-services business, money transmitter, or investment adviser, and that digital assets held through the platform are not insured by FDIC or SIPC.
The High Yield account materials describe an allocation linked to Strategy's STRC preferred security, while Bitcoin account materials involve exposure to bitcoin price movements. Castle's use of third-party providers for banking, advisory, custody, and transaction services means the overall user experience depends in part on those partners and applicable eligibility requirements.
