Peak terminology glossary 2025: The key peak season terms you need to know

How well do you know your eCommerce peak season ABCs? Before the holiday season comes around, brush up on some key fulfilment terms with our peak terminology glossary.

A — ABC inventory classification

Ranking products by sales velocity so A items (fast-moving) can be prioritised for peak access. 

B — Backorders

Orders placed on temporarily out-of-stock items, common when demand exceeds forecast. 

C — Cut-off date

The latest date a retailer can promise delivery by a certain date (e.g. Christmas Eve), factoring in processing and courier timelines. 

D — Dead stock

Inventory that doesn’t sell, often problematic post-peak if seasonal or perishable. 

E — Expedited shipping

Faster shipping methods (e.g. next-day or same-day), often in high demand during gift-buying season. 

F — First-time delivery success

The % of packages delivered without a reattempt, key for reducing customer service volume. 

G — Goods-in scheduling

Coordinating inbound stock arrival to avoid bottlenecks during seasonal surges. 

H — Holding costs

The expenses of storing inventory, which can spike if seasonal stock lingers post-peak. 

I — Inventory turnover ratio

A measure of how quickly stock sells and is replaced – critical for planning seasonal inventory levels. 

J — Just-in-time (JIT) fulfilment

Minimising storage by having products arrive at the warehouse just before they’re needed for shipping. 

K — Kitting

Assembling products into ready-to-ship bundles or gift sets, often more common during seasonal promotions. 

L — Labour flexing

The ability to quickly adjust workforce levels, often through agency partnerships or shift scheduling. 

M — Minimum order quantity (MOQ)

The smallest number of units a supplier will produce or ship – important to factor into seasonal demand planning. 

N — Network optimisation

The opening or improvement of new or existing network centres to position stock closer to customers, cutting costs and shipping times.

O — Overflow storage

Temporary space used when inventory exceeds normal warehouse capacity. 

P — Peak season

The busiest period of the year for fulfilment operations, typically spanning from October to January, driven by events such as Black Friday, Cyber Monday, Christmas, and Boxing Day sales. 

Real brands, real tales

Read the story of a daring mid-peak switch.

Start the adventure here

Q — Quick response (QR) inventory

A replenishment method allowing rapid restocking based on real-time demand signals. 

R — Real-time inventory sync

Keeping inventory counts accurate across channels (e.g. website, marketplaces) to avoid overselling. 

S — Seasonal staff

A temporary increase in staffing levels during peak periods to handle surges in order volumes.

T — Throughput

The volume of orders processed in a set time – a key KPI to monitor during seasonal peaks. 

U — Unplanned demand spike

A sudden, unexpected surge in orders, often triggered by viral trends or unanticipated events. 

V — Volume discount

Reduced courier or supplier rates for higher shipment volumes – often negotiated ahead of peak season. 

W — Wave picking

A method of grouping orders by shipping deadlines or courier cut-offs, improving speed during busy times. 

X — X-docking (cross-docking)

A distribution method where goods are transferred directly from inbound to outbound shipping with minimal storage time. 

Y — Year-on-year comparison

Analysing sales or operational performance against the same period in the previous year to forecast seasonal trends. 

Z — Zone picking 

A fulfilment method where warehouse pickers are assigned to specific areas, reducing travel time during busy periods.