# Payments With our investment API, we simplify the administration of cash payments and instant investments through automation. * [Setting up a mandate](/products/tol/guides/payments/mandate_setup/mandate_setup_intro) Setting up a mandate is the first step to enable automatic funding of a cash balance on our platform. With a mandate, a user authorises Upvest to collect payments on their behalf. * [Direct debit funding](/products/tol/guides/payments/direct_debit/direct_debit_intro) A direct debit funding is a process which results in an increase of the cash balance from the user's IBAN specified on their mandate. * [Cash balances](/products/tol/guides/payments/cash_balances/cash_balances_intro) Cash balance refers to the portion of our user's investment portfolio assets that reside in cash. Fundings, withdrawals, and all order processes affect the cash balance of an account group. * [Reference bank accounts](/products/tol/guides/payments/reference_accounts/reference_accounts_intro) Learn how to register and manage reference bank accouns for a user on the Investment API. * [Credit transfer testing](/products/tol/guides/payments/credit_transfer_testing) We will guide you through the process of simulating a money transfer for various movements that require cash settlements in one of our bank accounts.