Mid-August is traditionally seen as the heart of the back-to-school season, but an analysis of more than 88,000 real transactions made by ZEN.COM users over the past two seasons reveals a clear and recurring consumer pattern: a large share of basic school supplies is not bought “in advance” during the summer holidays, but only when a specific need emerges once classes begin. The highest number of purchases falls on the first Monday of the school year.
Back-to-school campaigns are now in full swing, with retailers competing for parents’ attention well before the school year begins. ZEN.COM transaction data shows, however, that when it comes to school supplies, the consumer calendar looks different from the campaign calendar.
In both 2024 and 2025, July and August remained below the level of an average month in terms of transaction volumes for stationery and school supplies, reaching just 76–83% of the monthly average for the respective year. A clear acceleration only came with the start of the school year: in September, the number of transactions rose to around 130% of the monthly average, almost one-third above the level of a typical month.
This suggests that some purchasing decisions are postponed until needs become specific — when parents and students know exactly which notebooks, materials, or supplies will actually be required.
The first school bell triggers the biggest wave of purchases
The pattern is clearest at the daily level. In both 2024 and 2025, the highest number of transactions for school supplies was recorded on the first Monday of the school year.
The start of classes therefore does not mark the end of the back-to-school season. For basic school supplies, it triggers its most intensive phase.
What increases most in September is the number of people making purchases. In 2024, the number of customers buying school supplies was 32% higher than in an average month. In 2025, the difference rose to as much as 53%.
For retailers, this means that the key indicator for the basic school-supplies segment is not the value of a single transaction, but the scale of the simultaneous influx of shoppers.
Electronics in summer, notebooks after the first school bell. Back to school has two different rhythms
Not all purchases related to the return to school follow the same pattern.
More expensive and planned purchases, such as electronics or footwear, are made throughout the summer. Basic, lower-cost school supplies, on the other hand, are much more heavily concentrated around the start of classes.
As a result, the back-to-school season has two distinct phases: larger, planned purchases made during the summer, followed by a September wave of quick, specific top-up purchases.
For retailers, this also means two different moments in which to reach the customer. In higher-value categories, the decision is made earlier. In basic school supplies, product availability, offer visibility and communication after the start of the school year become particularly important.
With bigger expenses, the final cost matters too
Back to school means spending across several categories at once — from notebooks and books to clothing, footwear and electronics. Consumers may therefore look not only at the shelf price or promotion, but also at the final cost of a purchase after additional benefits are taken into account.
One such mechanism is Instant Cashback, where part of the amount spent on selected purchases is returned directly to the user’s account. Among ZEN.COM customers who used this feature for back-to-school purchases, an average of PLN 80 per person was returned to their accounts.
The significance of such a mechanism varies by category. For more expensive, planned purchases, even a lower cashback rate can translate into a noticeable amount. For smaller purchases, what matters is their cumulative value over the entire season.
“The way consumers think about price is changing. They do not always wait for a sale — they buy when a real need arises, and what increasingly matters is how much the purchase ultimately costs them, rather than just the price displayed on the shelf. Instant Cashback fits well into this model because, instead of tying the benefit to a single promotional window, it allows customers to recover part of what they spend on a specific purchase. This is particularly relevant during the back-to-school season, which, as our data shows, does not end with the summer holidays but extends across different moments and different shopping needs,” says Łukasz Neska, Chief Growth Officer at ZEN.COM.
September does not close the season. For some categories, it is when it really gains momentum
School shopping does not end after the first few days of classes. It continues throughout the following weeks of September. Including the full month increases the number of transactions in the school-supplies category by around 60% compared with an analysis limited to July and August.
From a retailer’s perspective, this means that demand for the back-to-school category remains significant even when most summer advertising campaigns are already winding down.
This is a practical insight for retailers planning the duration of promotions, category visibility or media budgets. Scaling back communication at the end of August may mean withdrawing precisely when the largest number of customers starts shopping in some categories.
Methodology
The analysis is based on more than 88,000 real card transactions made by ZEN.COM users in Poland during the 2024 and 2025 back-to-school seasons across four categories: stationery and school supplies, books, children’s clothing and footwear, and electronics. The dataset was supplemented with data from the Instant Cashback programme.
