Carrier Performance Metrics: 8 Delivery KPIs Every High-Volume Retailer Should Track

Every carrier contract comes with a service level agreement, but most high-volume retailers will experience times when targets are missed. The delivery KPIs that matter are the ones that affect the retailer’s own parcels across every carrier, service and postcode, not the ones printed in the carrier’s brochure.

This guide sets out why carrier SLAs are not enough, the eight carrier performance metrics worth tracking, how to build a monthly carrier scorecard that compares carriers fairly and what should trigger action.

Why a carrier’s published SLA is not a performance measure

A published SLA describes the service levels a carrier aims to achieve across its network. It says nothing about the retailer’s parcel profile, its customers’ postcodes or the weeks when volume doubles. Ofcom’s 2025 research into parcel delivery found that 68% of UK recipients had experienced a delivery issue in the previous six months (Ofcom, 2025). For retailers, that is a reminder to measure performance on their own consignments rather than rely on a carrier’s headline network SLA.

The customer never sees the SLA either. Under the Consumer Rights Act 2015, goods remain the retailer’s responsibility until they are delivered, so a missed delivery lands on the retailer’s customer service team and its review score, regardless of the carrier used. Carrier performance metrics therefore have to be measured on the retailer’s own consignments, against the promise made at checkout.

The eight delivery KPIs every high-volume retailer should track

Each metric should be measured per carrier, service and lane, on the retailer’s own data:

On-time delivery rate: The share of parcels delivered within the promised window, measured against the date shown to the customer rather than the carrier’s own clock.

First-attempt delivery rate: The share of parcels delivered at the first visit; a failed attempt can add cost, create a customer contact and require a redelivery or alternative collection, which is one reason retailers offer out-of-home delivery as the fallback.

Delivery exception rate: The share of consignments that raise an exception in transit, such as address queries, misroutes or held parcels, tracked by cause

Loss and damage rate: Parcels lost, damaged or delivered short as a share of volume, with the value at stake recorded alongside the count.

Transit time against promise: The actual days from despatch to delivery compared with the service standard, reported as a spread rather than an average.

Scan compliance: The share of parcels with a complete scan history from collection to delivery, because a missing scan is usually where a lost parcel begins.

Claims resolution time: The days from a claim being raised to it being settled, plus the share of claims accepted, which shows how effectively the claims process works.

Cost per delivered parcel: Total carrier spend including surcharges, failed attempts and claims, divided by parcels successfully delivered rather than despatched, the honest version of cost per parcel.

Why network-wide averages hide underperforming carriers, services and postcodes

A blended on-time rate across the whole network can look healthy while one carrier, one service or one region is failing. A carrier that is strong on express parcels in the South East may be the weakest choice for economy parcels to rural Scotland. So looking only at an overall average can mask these variations.

The same applies over time. Three days of severe weather can push a strong carrier below a weak one for a month. So the scorecard needs to show trends as well as snapshots. Cutting the shipping KPIs by carrier, service, lane and week turns a reassuring average into an actionable decision, whether carriers are contracted directly or through managed multi-carrier delivery services.

Why a carrier’s published SLA is not a performance measure

A published SLA describes the service levels a carrier aims to achieve across its network. It says nothing about the retailer’s parcel profile, its customers’ postcodes or the weeks when volume doubles. Ofcom’s 2025 research into parcel delivery found that 68% of UK recipients had experienced a delivery issue in the previous six months (Ofcom, 2025). For retailers, that is a reminder to measure performance on their own consignments rather than rely on a carrier’s headline network SLA.

The customer never sees the SLA either. Under the Consumer Rights Act 2015, goods remain the retailer’s responsibility until they are delivered, so a missed delivery lands on the retailer’s customer service team and its review score, regardless of the carrier used. Carrier performance metrics therefore have to be measured on the retailer’s own consignments, against the promise made at checkout.

Building the monthly carrier scorecard – normalising across carriers, services and lanes

Carriers report in different formats and count different things, so the first job is normalisation. Define each KPI once, decide which timestamp counts as delivered, agree how a redelivery is treated and apply the same rules to every carrier. Then group results by service type and lane, so an express service is only compared with other express services on similar routes.

The scorecard should be concise enough to fit on a single page: the eight logistics KPIs by carrier and service, this month against last month and the same month last year, with volume alongside so a small sample cannot skew the ranking. Anyone in operations or finance should be able to read it in five minutes.

What should trigger action – investigation, volume reallocation or escalation, and why the review belongs before Peak

Set thresholds before the numbers arrive, so action is a rule rather than an argument. A single bad week usually warrants investigation with the carrier: was it weather, a depot issue or a change in the retailer’s own despatch cut-offs?

For example, two consecutive months below threshold on the same service can trigger a volume reallocation, moving affected lanes to an alternative carrier while the issue is addressed. Persistent failure or a rising loss and damage rate should be escalated to the carrier’s account team for a commercial review.

The review belongs in September and October rather than January. Peak volumes magnify every weakness in the network, and a carrier that struggles to meet its carrier performance metrics during a quieter period is unlikely to perform better under Black Friday demand. Retailers that settle the scorecard before Peak go into November knowing which carriers are best placed to take additional volume.

How a managed multi-carrier partner turns the scorecard into routing decisions

GFS is a managed multi-carrier delivery partner, not a carrier. Retailers ship through 1,000+ delivery services from one integration, so the performance of every carrier and service is captured in the same place and the same format. GFS can support retailers with carrier performance reporting across carriers, services and locations, giving teams a consistent dataset from which to build the monthly scorecard.

Because the carrier relationships sit with GFS, the scorecard leads somewhere. When a service underperforms on a lane, GFS’ operations team can work with the retailer to move volume to an alternative carrier through the same integration. GFS’ pro-active customer care team can identify exceptions early and work to resolve them before they become complaints.

Research by GFS and Retail Economics published in March 2026 found that only 24% of retailers feel fully confident managing multiple carrier partners (GFS & Retail Economics, 2026). A scorecard and a partner able to act on it can help close that gap.