The four-eyes principle, also called double approval, is a control mechanism that requires at least two people to review and approve an action before it takes effect. The name captures the idea: four eyes see the decision, not two. It is standard practice for payments, contracts, and any transaction above a set threshold.
The principle guards against both error and fraud. A second reviewer can catch a wrong amount, a duplicate payment, or a suspicious beneficiary the first person missed. It is simple, widely required by auditors, and effective, as long as the second review is real and not a rubber stamp.
That caveat is the weak point. Under time pressure, the second approval often becomes a reflex click: the two people confirm that an approval exists, not whether the underlying document is actually correct.
Phacet makes the second pair of eyes a substantive one. Before a human approves, the agent that controls supplier billing and the agent that verifies invoices against contract terms check the document against prices, contracts, orders, and deliveries, while the three-way matching agent confirms it all ties together. Approvers then sign off on a document already verified, with the reasoning exposed in a native audit trail.
The four-eyes principle adds a human reviewer. Phacet makes sure that reviewer looks at verified data, turning a rubber stamp back into a real control.
