A purchase management system includes a central database arrangement, a customer interface to the central database arrangement, and a bank specific database module, arranged to communicate with a transaction authorization module within a bank. The central database arrangement is arranged to receive, from a purchasing entity through the customer interface, purchasing rules applying to a purchasing group, and includes central processing means arranged to: add a selected purchasing group as metadata linked to a first transaction ID in the central database arrangement; add the purchasing rules applying to said purchasing group as metadata linked to the first transaction ID in the central database arrangement; and transfer metadata linked to the first transaction ID to the bank specific database module. The bank specific database module is arranged to receive a purchase approval request from the transaction authorization module, which purchase approval request comprises transaction information, including at least the purchase amount, linked to the first transaction ID.