Payments
Account updater
Account updater is a card network service that pushes reissued or renumbered card details to enrolled merchants so stored credentials keep working without customer action.
When it works the failure never occurs: a card that expired last month simply charges successfully. That makes it the single highest-leverage involuntary-churn intervention, because it costs no customer goodwill at all.
Coverage is not universal — it varies by network, by issuer and by how the credential was stored. Enrolment is nonetheless close to free relative to the recovery it produces, and it acts before the failure rather than after it.