> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vortexiq.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Label Generation Success, Japan Post

> Label Generation Success for Japan Post stores. Tracked live in Vortex IQ Nerve Centre. How to read it, why it matters, and how to act on it.

**Metrics type:** [Supporting Metrics](/nerve-centre/overview#metrics-types-explained)  •  **Category:** [Operational Health](/nerve-centre/connectors#connectors-by-type)

## 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 computes `successful_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](/nerve-centre/kpi-cards/japan-post/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](/nerve-centre/kpi-cards/japan-post/ems-cn23-customs-document-generation-failure-rate); a print-failure spike that surfaces on alerts is captured by [Label / Customs Doc Print Failures Spike](/nerve-centre/kpi-cards/japan-post/label-customs-doc-print-failures-spike). The 24-hour window keeps the reading tied to the current despatch shift.

## Reconciling against the source

There is no merchant-facing label-success dashboard at Japan Post; reconcile by comparing the count of accepted labels and tracking numbers issued in your own integration logs against the shipments visible in Web Yu-Pri (Yu-Pri My Page) for the same 24 hours, and split rejected calls into 4xx (your payload or token) and 5xx (Japan Post infrastructure). Timestamps in Japan Post tooling are carrier-local (JST).

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### Tracked live in Vortex IQ Nerve Centre

*Label Generation Success* is one of hundreds of KPI pulses Vortex IQ tracks across Japan Post and 70+ other ecommerce connectors. Nerve Centre runs the detection layer; Vortex Mind investigates the cause when something moves; Ask Viq lets you interrogate any number in plain English.

[Start for free](https://app.vortexiq.ai/login) or [book a demo](https://www.vortexiq.ai/contact-us) to see this metric running on your own data.