Five Edge Cases That Break a Simple SaaS Referral Program

A referral program that pays commissions on real money is far more complicated than it first appears. The team building one for their SaaS product focused on five tricky cases, starting with a visitor who clicks multiple promoter links, where they chose a first-touch rule to keep the first valid code. To block self-referral abuse using multiple email addresses, they normalize Gmail addresses and compare phone numbers, flagging unusual patterns for manual review rather than blocking automatically. To prevent duplicate commissions from repeated payment confirmations, the database enforces uniqueness on the payment record, and commissions are held for 30 days to cover refunds. The article also describes splitting out GST so commission is calculated only on the base price, with payouts currently made manually.