UK shoppers spent £26.9bn – £28bn online between November and December 2025, according to Adobe and Salesforce – both reporting record figures for the holiday.
None of the excess demand made Peak easy for retailers. Traffic kept climbing, but conversion and margin came under real pressure, and that’s really where this year’s story sits:
What happens once demand shows up?
How long does the trading window actually last?
How quickly do problems get caught and fixed before customers notice?
Can warehouse and delivery teams stay consistent for weeks rather than days?
Does AI traffic convert the way retailers hope?
Can carriers scale their capacity to keep pace with all of it?
Five factors, in our view, decide who has a strong Peak season this year. Here’s our rundown of where the pressure points sit.
Black Friday used to be a single, sharp spike in demand. Retailers built their whole operating plan around surviving one weekend: extra staff, extra stock, extra warehouse capacity, then back to normal by the next week.
That model no longer holds. Promotions start in early November. Shoppers browse for weeks, building wish lists and comparing retailers, before they commit to anything. PWC still forecasts £6.4bn in UK Black Friday spend this year, so the day itself hasn’t lost its weight, but it’s no longer where all the pressure concentrates.
The shift extends further beyond Black Friday. This summer, Amazon introduced a new ‘Peak Adjacency’ surcharge in the weeks surrounding Prime Day, applying the same seasonal cost logic it has traditionally reserved for Q4. Peak, it seems, is no longer a single season on the calendar. It’s a recurring condition retailers and their logistics partners now have to plan around at multiple points in the year.
What ‘being ready for Peak’ means has shifted accordingly. It’s less about bracing for one weekend and more about holding stock accuracy, delivery reliability and service levels steady across extended trading windows, wherever they fall. At the same time, margin pressure builds quietly in the background throughout. Retailers still planning capacity as though Peak is a single event risk running out of steam well before any of these windows close.
Shoppers are taking longer to decide. IMRG data from Peak 2025 showed traffic rising across the sector, while revenue often didn’t keep pace, a sign that visits alone were no longer a reliable predictor of sales.
What shoppers are weighing up before they buy has moved beyond the product itself to consider the entire purchase as a whole. Delivery timing, returns clarity and stock accuracy can carry real weight in that decision, and the questions surface right at the moment someone is deciding whether to check out.
A vague delivery promise or unclear policy reads as risk, and cautious shoppers act on it. IMRG and Revlifter both pointed to the same pattern through Peak 2025: retailers who could speak confidently about delivery and stock at the point of purchase saw stronger conversion.
The retailers pulling ahead close the gap between spotting an issue and fixing it fastest, often before it ever reaches the customer.
A longer Peak trading window puts more strain on the people and infrastructure behind every delivery estimate and stock message, for far longer than used to be demanded in Q4.
Retail Gazette and GFS both flagged fulfilment strain and labour pressure as defining features of Peak 2025, concentrated around what the industry called the ten days that matter most. The intensity now spreads across six or more weeks instead of a number of days, with warehouse, delivery and service teams expected to hold that pace for the duration.
Headcount and fleet plans built for a short, sharp Peak strain under that kind of sustained load. A driver rota sized for one heavy weekend behaves very differently across a month and a half of steady volume. A warehouse team that holds up fine for ten days can start losing accuracy by week four.
Capacity planning needs to catch up with everything already covered here. The delivery reliability and stock accuracy customers expect only holds if the workforce and infrastructure behind it can sustain that pace for as long as Peak actually runs.
AI-assisted shopping is transforming both how much people spend and how they decide what to buy. Walmart reports 35% larger baskets among shoppers using its AI assistant. Amazon’s Rufus drives 60% higher purchase completion. Adobe puts AI-referred traffic at 31% higher conversion than any other channel, nearly double the rate from the year prior, and that gap widens further during Peak, with some reports showing 38% higher on Black Friday.
The bigger shift sits earlier in the journey than conversion. AI agents don’t shop by browsing. Given a task, they weigh the options available to them and select whichever is most likely to deliver a successful outcome, factoring in availability, delivery speed and fulfilment reliability, alongside price and brand. A product that’s out of stock, slow to deliver or inconsistently fulfilled can be deprioritised or left out of the recommendation entirely, regardless of how strong the product or the marketing behind it is.
Fulfilment, in other words, now shapes whether a product gets seen, not just whether it gets bought. Retailers who get delivery and inventory wrong during Peak risk losing more than a sale at the point of purchase. They risk never being surfaced to the shopper in the first place.
Getting this right takes preparation well before Peak begins. Inventory accuracy, delivery speed and fulfilment reliability all need to be in place ahead of the demand, not adjusted once the trading window is already underway.
Retailers can’t deliver on their promises without a robust operational network behind them. A carrier moving a retailer’s goods experiences the same strain during Peak.
A longer trading window spreads the same volume across more weeks and asks fleets to hold steady the whole way through without changing the physical work of getting goods from A to B. Amazon’s decision to introduce a Peak adjacency surcharge around Prime Day this year is a sign of how far that pressure extends beyond the traditional Q4 window.
Carriers facing that kind of surge have a choice much like the retailers they serve: turn away volume they can’t cover or find a way to flex capacity at short notice. On-demand courier networks give them that option, whether that means moving stock between warehouses to relieve a site running short or offering an extra vehicle and driver to join your carrier’s fleet for instant capacity.
Retail success at Peak has never rested on the retailer alone. It depends just as much on whether the carriers behind them can flex to match demand, exactly when and where it happens.
The retailers who come out ahead this Peak will be the ones whose fulfilment operation holds up across six weeks instead of one, stays visible to the customer at the point of purchase, keeps pace with labour and capacity strain, gets surfaced by AI tools shoppers increasingly rely on, and is backed by a carrier network that can flex when delivery shifts.
Zippd is a technology-led logistics partner built to add flexibility and speed to any point in that chain. We operate a UK-wide network of on-demand couriers, giving retailers and carriers a way to add capacity exactly when and where it’s needed, without committing to it year-round. Same-day and next-morning delivery, with cut-off times built around how late Peak trading actually runs, means brands can extend their delivery promise deeper into the day without expanding their own fleet.
Our network and technology mean new services can go live in days, not months. Activate your Peak 2026 solution today: Talk to an Expert