Visa operates a massive wholesale funds transfer settlement network—making and receiving over 2,000 payments daily from the financial institutions that issue its cards and pay merchants. Total settlements top $3 trillion annually, so the benefits of netting those payments and making or collecting just one payment daily for each financial institution (FI) would be huge. But netting had long been impossible because FIs weren't making or collecting one payment but thousands of discrete payments that had to be tied to separate business units or purposes. The source or destination of payments had to be identified or it would disrupt efficient processing by the FIs.

Visa treasury solved the netting challenge in 2010 by writing an application that allows it to consolidate payments to and from some of its large FI customers without impacting their operations, explains Richard Laiderman, Visa's treasurer. Consolidated net payments now include the amount, direction of transfer and payment address for every individual client business unit transaction. The difference is that after netting, these multiple payments are no longer with Visa but are executed internally by the client FI with information supplied by Visa.

The challenge for Visa treasury and IT was to enable a single net settlement transaction daily but keep the components of the settlement transparent to the FI so its legacy systems could continue to post them all as usual, explains Malini Dutta, Visa's chief software engineer. Now payments are exchanged in a customer consolidation account rather than a Visa settlement account. This ultimately meant "reinventing our entire settlement systems process," notes Jo-Anne Rodrigo Sevilla, another Visa software engineer, "as work on the many components revealed new complexities."