At a glance
Mean number of calendar days between the first carrier scan and the delivered scan, averaged across every Shippo-printed shipment that reached a delivered state in the trailing 30 days, compared against the prior 30 days. The “how long does a parcel actually spend in the network?” number, blended across all underlying carriers (USPS, UPS, FedEx, DHL and any regional carrier Shippo routes to). The alert fires above 5 days, which for a mostly-domestic US merchant signals a slow lane, a backlogged carrier, or a mix-shift toward ground services.
What it tracks
The card reads the Shippo tracking timeline for each shipment (GET /tracks/{carrier}/{tracking_number}, or the cached tracking_history on the transaction) and measures the gap from the first TRANSIT (or PRE_TRANSIT to first physical scan) event to the DELIVERED event. It averages that gap, in calendar days, across all delivered shipments in the 30-day window and compares it to the prior 30 days. Because Shippo aggregates many carriers, the figure is a blended transit time: a USPS Ground Advantage parcel (typically 2 to 5 days) and a USPS Priority parcel (1 to 3 days) both feed the same mean, so a shift in service mix moves this card even when no single carrier slowed down. Scan timestamps arrive in carrier-local time and Shippo’s tracking ingestion can lag the physical scan by minutes to a few hours, so day-boundary rounding is the usual source of small wobbles. The number excludes in-flight parcels (no delivered scan yet) and returns labels.