Transactions that are processed by One Community (SEPA Direct Debit & bank transfer) can be cancelled by browsing to the transaction (Finance > Transactions) and clicking on 'Cancel' on the top. Direct debit transactions cannot be cancelled while in progress, because they are already presented to the bank.
Transactions that are processed by an external payment service provider (such as iDEAL, Adyen, Mollie or Buckaroo) should be cancelled through their interface. The payment service provider will notify One Community about the mutation and the status will be updated accordingly.
Transactions will expire automatically. The expiration time depends on the payment method.