Rule: Prior chargeback (premium)

Rule key: chargeback_history · Default weight: 1.0 · Tier: Business / Enterprise

The single highest-accuracy rule, because it uses your own confirmed fraud history. Requires the chargeback webhook integration to be configured.

Two evaluation passes

Direct atom hits. Does the current order share an atom (email, device, phone, card BIN+last4) with any prior order that received a chargeback?

Atom	Base score
Email previously charged back	80
Device previously charged back	80
Card previously charged back	75
Phone previously charged back	60

Cluster hits. The order-graph linker finds prior orders linked to the current order by any shared atom, then counts how many of those linked orders received chargebacks. Each cluster chargeback adds 20 points (capped at 60).

Why this matters

A buyer who chargedback as alice@gmail.com on order #1001 and now shops as bob@example.com on order #2050 will be caught by this rule via shared device fingerprint, IP, phone, or card BIN. The closed feedback loop means your detection accuracy increases every time a chargeback comes in.