A product can appear commercially healthy while quietly consuming more margin than expected. The purchase price may be stable and sales may remain active, yet freight adjustments, customer discounts, damaged units, return handling, small-order costs and awkward fulfilment can steadily weaken the result. For a small UK trading business, the problem is rarely solved by looking at one headline percentage. A useful margin review follows the product through the way it is actually bought, stored, sold and supported, then identifies costs or concessions that have become normal without being deliberately accepted.
Start with the commercial path of the SKU
Choose a manageable group of products and map the steps between supplier order and completed customer sale. Record where the business commits money, handles stock, changes price or performs extra work. This creates a practical view of the SKU rather than treating purchase cost and selling price as the whole economics. The exercise can reveal products that require unusual repacking, frequent manual checking or repeated customer clarification. None of those activities automatically makes a product unattractive, but they should be visible before the team assumes that two similarly priced items contribute equally.
Separate predictable landed costs from occasional exceptions
Freight, supplier charges and inbound handling can vary between orders. A business should distinguish normal costs that belong in routine commercial thinking from genuine exceptions. If a supposedly exceptional charge appears repeatedly, it may need to become part of the product's expected cost model. Avoid false precision where records do not support it. The aim is to build a defensible working view using costs the business can trace, then flag gaps that need better capture rather than filling them with estimates that later look authoritative.
Review discount behaviour by product and customer type
Discounting can leak margin gradually because each individual concession appears reasonable. Look for products where staff routinely reduce price to close a sale, meet a marketplace expectation or satisfy a particular customer group. The important question is not whether discounts exist but whether the business understands their pattern. A product with frequent discretionary reductions may need clearer pricing rules, a different bundle, stronger product information or a review of the customer segment being targeted. Recording the reason for material discounts makes future analysis more useful than simply storing the final selling price.
Bring returns and defects into the commercial picture
A returned product creates more than a refund. Staff may need to receive it, inspect it, decide whether it can be resold, correct stock records and answer follow-up questions. For 3C products, compatibility misunderstandings can also create avoidable returns even where the item itself is sound. Review return reasons alongside product economics and look for repeated causes. Better compatibility wording, clearer images or improved pre-sale information may protect margin more effectively than a price increase because they address work that should not have been created in the first place.
Identify fulfilment work that the price does not reflect
Some SKUs are disproportionately difficult to pick, pack, store or ship. Others require staff to combine components, locate accessories or check serialised information before dispatch. These operational differences can disappear when the business reviews sales only at category level. Ask warehouse and customer-service staff which products repeatedly need intervention. Their observations should then be checked against records rather than treated as automatic proof. Where the pattern is real, the business can decide whether to change the process, packaging, minimum order, product configuration or commercial treatment.
Look for range complexity that creates indirect cost
A long tail of similar variants can make purchasing and selling harder even if each individual SKU looks acceptable. Staff must distinguish versions, maintain descriptions, manage images and answer compatibility questions. Slow-moving variants can also fragment stock investment. Review whether each variation serves a distinct customer requirement or exists mainly because it accumulated over time. Rationalising a range is not simply about deleting low-volume products; it is about understanding whether the choice creates enough value to justify the operational attention and inventory complexity attached to it.
Turn findings into specific commercial decisions
A margin review is useful only if each material issue receives an action. One product may need revised pricing, another clearer compatibility data, another a supplier discussion and another a controlled exit from the range. Assign an owner and record why the decision was made. This prevents the same issue being rediscovered several months later without context. Where evidence is incomplete, make the next action a data task rather than pretending a commercial conclusion has already been reached.
Repeat the review where change is most likely
Product economics are not static. Supplier terms, freight arrangements, customer behaviour and return patterns change. A small trading business does not need to recalculate every SKU continuously, but it should know which events justify another look. Supplier price changes, repeated discounts, rising returns or a change in fulfilment method are sensible triggers. A focused margin-leakage review gives managers a more useful question than “does this product sell?” It asks whether the product still earns its place after the real work and concessions surrounding the sale are understood.