Full stack billing platforms are evolving as software companies adopt mixed pricing models and generate richer usage data. These systems manage subscriptions, invoicing, usage metering and revenue workflows while integrating with finance and CRM tools. This article presents seven startups building end to end billing infrastructure for modern B2B software.

AI native and agentic products generate dense event streams and fast changing costs, which creates new needs for pricing and billing. These platforms capture fine grained usage, support micro billing units and enable flexible models suited to AI workloads. This article presents five startups building billing tools designed for AI and agent based software.

Usage metering and pricing engines help software companies turn raw activity data into clean metrics and rated values that drive modern pricing models. These systems ingest events, apply pricing rules and feed billing platforms with accurate usage. This article presents four startups building infrastructure for usage based and hybrid monetisation.

Lightweight billing tools serve teams with simple subscription or pay as you go needs by offering fast setup, ready made payment flows and minimal configuration. They focus on essential billing tasks rather than full revenue operations. This article presents five startups building accessible billing solutions for small SaaS teams, indie developers and freelancers.