In July 2013 Massachusetts lawmakers voted to switch the rules for sourcing sales of services in its income apportionment formula, moving from a statutory “cost of performance” method to a “market-sourcing” approach. The Massachusetts Department of Revenue (DOR) predicts that the new law will generate up to $37 million annually. In addition to increasing revenue, the new rules are intended – at least in part – to eliminate the many disputes between DOR and taxpayers regarding interpretation of the old cost of performance rules.