Tabs has raised $55 million in Series B funding led by Lightspeed Venture Partners to scale its AI agents for finance automation, processing over $1 billion in annual invoice volume across 200+ enterprise customers. The financing addresses a critical bottleneck: 75% of accountants are nearing retirement while the number of new CPAs has dropped 30% in the past decade, even as revenue operations become increasingly complex with usage-based and hybrid pricing models.