Field note
Refunds that arrive after the cohort was declared healthy
30 June 2026
Store refunds can land weeks after a renewal. A cohort marked stable in week two can be leaking in week six without anyone updating the letter to the board.
Google and Apple refund windows do not respect your cohort close. A family plan cancelled after a school holiday can reverse a charge you already recognised. If the refund file is only opened at quarter end, the pretty curve has already been shown upstairs.
We keep a simple rule in diagnostics: no cohort sentence in a pack unless the refund file for that window has been joined, even if the join is ugly. Ugly is honest. A stable curve with a missing refund file is a rumour.