Harpy Glossary

OTDR (On-Time Delivery Rate)

Amazon & D2C glossary · Harpy Media

OTDR (On-Time Delivery Rate) is the share of merchant-fulfilled parcels delivered to customers by or before the promised delivery date. It is measured on tracked packages over a rolling window, and it is one of the performance metrics that decide whether an FBM seller keeps their privileges.

What is OTDR?

The threshold is operationally strict, and the consequences are immediate. Fall below it and merchant-fulfilled selling privileges can be suspended; sustained breaches cost Buy Box eligibility across the catalogue, which means the storefront stays open while nothing in it can be bought easily. For an FBM seller, OTDR is not a reporting footnote — it is the licence.

What the metric measures, and why it is unforgiving

The calculation compares final delivery scans against the estimated delivery date the customer was shown. That means the promise itself matters: if your shipping templates advertise aggressive transit times to look competitive, you have tightened your own target, and a carrier having a bad week becomes your metric failing rather than theirs. Conservative, accurate promises are the safest foundation.

The rolling window means it responds to recent behaviour rather than punishing history permanently — but it also means a cluster of late packages in a bad fortnight moves the number sharply. A single storm, a carrier’s sorting-hub failure, or a peak-season backlog can push the rate down fast if the baseline promise left no room for variance.

How to protect it

Set delivery promises from measured performance, not aspiration. Use shipping setting automation or carrier-calculated dates where available, so the estimate the customer sees reflects real network speeds rather than a template guess. Then build buffers for the seasons you know about: the fourth quarter, weather-affected lanes, and periods when carriers are absorbing everyone’s volume.

Monitor the metric continuously, and treat a downward trend as a logistics problem to solve rather than a number to explain. Where a lane consistently fails, change the carrier or extend the promise. Where a peak is coming, adjust expectations in advance — a slightly slower honest promise protects the account better than a fast one that cannot be kept.

OTDR (%) = (Packages Delivered On Time ÷ Total Tracked Packages Delivered) × 100Measured on a rolling window against the estimated delivery date the customer was shown. Conservative shipping promises are as much a protection as fast carriers.

In practice

An FBM brand connects its warehouse system to shipping setting automation, so each order automatically selects the carrier service with a delivery estimate calculated from live network speeds. Parcels arrive on or before the date the customer saw, the rate holds near-perfect through the season, and the account keeps both its privileges and its position on the page — without anyone manually reviewing carrier performance.

⚠️ Watch out. A competing seller hard-codes aggressive transit times into shipping templates to look more competitive than the network can actually deliver. When a regional storm delays a carrier’s sorting hubs, a large batch of that week’s orders misses the promised date, and the rate collapses far below the threshold. Automated review revokes merchant-fulfilled privileges mid-quarter, stranding inventory and converting a temporary weather problem into an account-level crisis.

💡 Harpy tip. Promise what you can prove. Use carrier-calculated or automation-driven delivery dates, keep lane performance data, and review the metric weekly — rising transit times in one region are a warning you can act on before they become a breach. When in doubt in peak season, promise a day slower and deliver a day early.

How Harpy Media helps

FBM delivery performance is monitored inside our account routines: shipping promises calibrated to real carrier speeds, lane performance tracked, and the metric reviewed weekly rather than discovered in a notification.

OTDR FAQ

What is the required On-Time Delivery Rate on Amazon?

Amazon expects merchant-fulfilled sellers to keep OTDR at or above its stated threshold (commonly cited as 90% for tracked packages delivered on time). Breaches risk suspension of FBM privileges and Buy Box eligibility, so the working target should be well above the floor.

Does OTDR apply to FBA orders?

No — it applies to merchant-fulfilled packages, where you control the carrier and the delivery promise. FBA deliveries are Amazon’s responsibility and are measured through different performance indicators.

How can I improve my OTDR?

Use realistic delivery estimates (carrier-calculated dates or shipping setting automation), select carriers by measured lane performance, add transit buffers during peak periods and bad weather, and adjust promises before a known disruption rather than after it has cost you the metric.

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