Industry growth has coincided with significant SaaS accounting changes. Among the most recent — and impactful — are ASC 606 and IFRS 15. FASB's ASC 606: Revenue from Contracts with Customers replaces the rules in ASC 605: Revenue Recognition, while IFRS also amended its guidance to match FASB rules more closely (but not exactly) with IFRS 15: Revenue from Contracts with Customers. In both cases, the rules state that a significant percentage of a SaaS company's revenue and expenses must be recognized over the service subscription life rather than when they are received or incurred. That has created a globally standardized — albeit complex — set of rules for SaaS accounting that apply to companies if they meet certain criteria, namely: The company retains sole possession of the software, and customers have no contractual right to take possession of the software, unlike when licensing or purchasing software. Customers may not run the software on their own or a third-party's hardware. The company's employees administer the SaaS services, and delivery of performance obligations cannot occur by the customer or a third party. Most SaaS providers fulfill all three criteria, making specialized accounting rules widely applicable to this market.