California's corporate tax rate is a flat 8.84%, with a minimum franchise tax. Arizona's is a tiered rate, potentially lower for smaller companies. California's personal income tax is much higher, especially for high earners you might hire. Arizona's is lower and more favorable. Sales tax on SaaS is complex, but both states tax it; however, the rates and specific rules differ. California offers some credits, like the R&D tax credit, but competition for them is fierce. Arizona also has targeted incentives, particularly for companies creating jobs.