At a glance
Share of Japan Post label and manifest requests that produced a printable, accepted label over the trailing 24 hours. It is the despatch-floor heartbeat: when it dips, parcels cannot leave the warehouse because the shipping document will not generate. The card alerts below 98 percent, because at despatch volume even a 2 percent failure rate means a meaningful pile of stuck orders by lunchtime.
What it tracks
The card computessuccessful_label_calls ÷ total_label_calls over the rolling 24 hours, counting a call as successful only when Japan Post returns an accepted label with a tracking number and (for international) the associated customs paperwork. The Japan Post label set spans domestic Yu-Pack and Yu-Pack Cool, Letter Pack, and international EMS, and EMS is where most failures land because the request must also carry a valid CN23 customs declaration: a missing HS code, an over-length item description, a prohibited-goods flag, or a destination Japan Post does not currently serve will all bounce the call. Domestic label failures are usually simpler: a malformed address, an unsupported prefecture-zone weight band, or an expired auth token. Because the same auth and transport layer underpins every Japan Post call, a sustained dip here moves in lock-step with API Error Rate, so check that card first to separate “Japan Post is down” (5xx) from “our request was rejected” (4xx). The deeper customs failure mode for EMS exports has its own dedicated card, EMS CN23 Customs Document Generation Failure Rate; a print-failure spike that surfaces on alerts is captured by Label / Customs Doc Print Failures Spike. The 24-hour window keeps the reading tied to the current despatch shift.