Cross-selling is suggesting a different product or service that goes with something a customer is already buying or has bought, such as a case and screen protector with a phone, or a gutter clear-out added to a roof repair. Unlike an upsell, which offers a better or larger version of the same item, a cross-sell adds something new to the order.
How cross-selling works
Cross-sells appear at several points in the buying journey:
- On the product page, as “goes well with” or “complete the look” suggestions.
- In the basket, where a small, cheap add-on such as batteries or a care kit is easy to accept.
- On the confirmation page or in a post-purchase email, once the main purchase is safely done.
- In ads, where catalogue campaigns can show recent buyers items related to what they bought.
- In conversation, when a sales or service team suggests a related service at the right moment.
The suggestions can be chosen by hand, built from “frequently bought together” patterns in your order data, or generated by a recommendation app using personalisation based on browsing and purchase history. Hand-picked rules are often better for a small catalogue, because you know which items genuinely belong together. Automated suggestions earn their place once you have enough orders for the patterns to be real rather than coincidence.
Why it matters
A good cross-sell raises average order value without the cost of finding a new customer, and it often improves the customer’s experience: the person who buys a paddleboard really does need a pump. Over time it also widens what each customer buys from you, which gives them more reasons to come back.
UK law shapes how you do it. Under the Consumer Contracts Regulations 2013, an extra paid item must not be added through a pre-ticked box; the customer has to choose it. Slipping add-ons into the basket without the shopper asking is also a design practice the CMA treats as a consumer protection risk. Cross-sells should be offers the shopper actively accepts, never defaults they have to spot and remove.
Common mistakes
- Suggesting items that do not relate to the purchase, which looks like noise and trains people to ignore the space.
- Crowding the checkout with offers, so the shopper is distracted from paying.
- Pre-adding paid extras to the basket or pre-ticking them.
- Recommending products that are out of stock or do not fit the item being bought.
- Measuring how often the cross-sell is added but not whether it is profitable or returned.
- Pushing another product straight after a complaint or a delivery problem.
How to act on it
Start with your order data. Find the pairs of products that are already bought together, and the items customers buy a few weeks after their first order. Pick three to five obvious pairings and place them on the relevant product pages and in the basket. Some products work better offered as a product bundle with a small saving than as a separate suggestion.
Then extend it after the sale: a well-timed email once the order has arrived, suggesting the item that completes it. In paid social, catalogue and dynamic product ads can show past buyers related products from your catalogue, which works best when the product sets are built from real buying patterns. Judge every cross-sell on the profit it adds and its return rate, not only on how often it is accepted.