In this guide 6 sections
A style is the design, a colourway is that design in one colour, and a size is one measure of it. A SKU is the exact combination of style, colourway and size that a packer can lift off a shelf and a stocktake can count. A barcode is what the scanner reads. A variant is what the shopper picks.
One shirt, five layers of detail
Take an Oxford shirt. The collar, the cut and the fabric make the style, and the style gets one code, such as OXF100, that never changes whatever colour or size you sell.
Sky blue and white are two colourways. Each gets a short colour code, so the sky blue shirt becomes OXF100-SKY, and a medium in that colour is the SKU OXF100-SKY-M. That code is what sits on the shelf.
The barcode is separate. It is the number printed on the hangtag, usually an EAN or UPC, and it points to exactly one SKU, so scanning it brings up OXF100-SKY-M.
- Style: OXF100, the design and the fabric
- Colourway: SKY, the shade or print
- Size: M, one row on the size chart
- SKU: OXF100-SKY-M, one countable item
- Barcode: the hangtag number that points to that SKU
A pair of shoes adds width and half sizes
Shoes multiply faster than shirts. A loafer in two colours, ten sizes and two widths makes forty SKUs before a single half size is added, and each one needs its own barcode.
Size also carries a system. A UK 8, US 9 and EU 42 can describe roughly the same foot, so store one size on the SKU and keep conversions in the size chart.
Width belongs in the SKU too. A wide eight and a standard eight look alike in a photograph yet cannot be swapped on a shelf or in a return parcel. The last, the foot-shaped mould a shoe is built on, also splits one style into two when the men’s and women’s versions differ in shape.
What the storefront calls a variant
Variants live on the product page. Each variant carries its own price, stock count, barcode and weight, while the product above it holds the shared photographs, description and size chart.
Platforms differ on this point. Some treat each colourway as its own product, while others make colour an option on one product and let the variants hang beneath it. Marketplaces add parent and child listings, where the parent is the style and each child is a SKU with its own barcode.
Settle where each attribute lives before loading.
- On the style: description, fabric, size chart, care instructions
- On the colourway: colour name, photographs, swatch
- On the SKU: stock count, barcode, weight, bin location
What breaks when the terms are mixed up
Counting at style level hides the gap. A report that says forty shirts are in stock for OXF100 does not reveal that the large is gone and the mediums are piled up in the back.
One barcode on a whole style is worse. Every size scans as the same item, so a mixed delivery is received as one count and the shelf drifts away from the system within days.
Reused SKUs corrupt history. Last season’s sales of a discontinued navy get credited to this season’s olive, and marketplaces reject two listings that share a barcode.
- Sold-out sizes still shown as available
- Pickers sent to the wrong size
- Returns restocked into the wrong colourway
- Sales reports that blend two seasons
- Marketplace listings rejected for duplicate barcodes
Set the code rules once and write them down
Codes outlive their authors. Fix the order of the segments, the length of each and the separator, and keep the season out of the code, because last season’s style may sell again.
Avoid look-alike characters, such as O and zero, and never put a space or a slash in a SKU, since importers and label printers choke on both. Never reuse a retired code.
Write the rules on one page. Then check ten random SKUs from your catalogue against it this week, because every mismatch shows where the next import will go wrong.
Catalogue code rulebook
One page, three blocks. Block one fixes the code format. Block two is a table showing whether each attribute, from fabric to barcode to bin location, lives on the style, the colourway or the SKU. Block three holds worked rows for a shirt and a pair of shoes, so a new merchandiser can copy the pattern instead of inventing one.
Open a blank worksheet to printQuestions owners ask
Is a SKU the same as a barcode?
No. A SKU is your own code. A barcode is a number printed on the pack for scanners, and it may come from a manufacturer or a registry rather than from you. Your system keeps the link between the two.
Should the season go in the SKU?
Keep it in a separate field. A season inside the code forces a new SKU whenever a style returns, and the sales history of a steady seller gets split in two.
When does a change need a new style code?
When the product looks or fits differently. A new fabric, a new cut or a new fit needs a new code, while a trim change that no buyer would notice can keep the old one.
Who should own the code rules?
Give it one owner, usually the merchandiser or the catalogue manager. Everyone else asks that person for new codes, so duplicates and typos never reach the system.