Abstract: A payment transaction system, including a transaction exchange for: (a) registering and certifying account keepers for maintaining accounts and authorising payment transactions on behalf of entities; (b) storing account keeper identification (ID) data; (c) receiving a payment transaction, said transaction including ID data for a registered account keeper and an account associated with a payer making a payment of the transaction, and ID data for a registered account keeper and an account associated with a receiver receiving the payment; (d) determining validity of the transaction based on the ID data; and (e) authorising the transaction with the account keeper associated with the payer.