Methods and systems are presented for enabling an online service provider to process transaction requests according to a dual control workflow using multiple transaction processing systems that are only configured to process transaction requests according to a single control workflow. A dual control module is implemented between an interface server and the transaction processing systems. The dual control module may intercept transaction requests from the interface server. The dual control module may withhold transaction requests from being sent to any one of the transaction processing systems until a set of criteria is satisfied according to the dual control workflow. The dual control module may obtain approvals and/or denials from designated approvers. Once the set of criteria is satisfied for a transaction request, the dual control module may forward the transaction request to one of the transaction processing systems for processing.