Best free SaaS dunning management tools

There are roughly 15-25 legitimate dunning management tools on the market, but only 3-4 offer meaningful free tiers, and most are either enterprise-only or bundled features inside larger payment platforms like Stripe or Chargebee. The core pain point is clear: failed payments account for 4-8% of MRR loss for typical SaaS companies, yet small and mid-market vibecoders either can't afford dedicated tools or settle for basic retry logic built into their payment processor. The real gap isn't in the feature set — it's in accessibility and transparency. Most free dunning tools have severe limitations (single retry rule, no customization, limited reporting) or dark patterns that upsell aggressively after day 7. A founder entering this space should focus on two things: (1) an honest, truly functional free tier that handles at least 50-100 failed transactions/month with configurable retry schedules, and (2) transparent pricing that makes upgrading feel earned, not forced. The opportunity exists because the market is fragmented between Stripe's basic dunning and expensive standalone tools; there's white space for a lightweight, free-first player that doesn't treat small businesses like future unicorns.