Naming SKUs for colour and size variants

A thermos flask in five colours and four capacities is 20 SKUs. With 40 such models, it is 800. Without a naming rule, everyone names things in their own style, and a few months later the table holds TB210black500, tb-210-bk-500ml and something only the storekeeper understands, "the small black one". Mismatched barcodes, split stock and counts that do not tie all begin here. A simple naming rule that can grow is the cheapest data tidying there is.

A SKU in four segments

Split the SKU into fixed segments joined by hyphens:

• Category: two or three letters, for example TB for thermos bottle.
• Model: four digits, for example 0210.
• Colour: two letters, for example BK black, WH white, RD red, BL blue, GY grey.
• Specification: capacity or size, of fixed length, for example 0350, 0500, 0750 and 1000 for millilitres.

Together they give TB-0210-BK-0500: model 0210 thermos, black, 500 ml. Fifteen characters, readable at a glance by a storekeeper and easy for a scanner.

Not every product has a colour or a specification. Leave that segment out entirely, or fill it with 00, but keep it consistent within a product type. A single marketplace product page often holds several variants; each variant gets its own SKU, and the page must not be treated as one SKU, or stock cannot be separated by colour and size.

Seven rules

1. Segments always come in the same order and each has a fixed length, padded with leading zeros.
2. Use capital Latin letters, digits and hyphens only: no spaces, slashes or accents, and certainly no Cyrillic letters or Chinese characters.
3. Put nothing in the code that changes, such as price, supplier or season.
4. Do not use abbreviations that only one person understands. Register every colour and specification in a small dictionary and use the dictionary's codes.
5. A new colour or specification goes into the dictionary before any SKU is created.
6. A retired SKU code is never used again.
7. Each SKU has its own barcode; do not let all colours share one model barcode.

Why fixed length and zero padding

Sorting is the quickest test, and the strongest reason for fixed length. Suppose capacities are written without padding, 1000 and 500. Sorted as text in Excel, 1000 comes before 350 and 500, because text is compared one character at a time. Padded as 0350, 0500, 0750 and 1000, the order matches what you expect.

Sizes behave the same way. Sorted alphabetically, S, M and L come out as L, M, S. Use numbers instead, 01 for S, 02 for M, 03 for L and 04 for XL, and record the meaning in the dictionary.

Doing the arithmetic

One model, 5 colours times 4 specifications, is 20 SKUs. 40 models make 800. Add one more colour and every model gains 4 SKUs, which for 40 models is 160 more at once.

At that volume nobody can rely on memory, and filtering and sorting in Excel work only if the codes are regular. A fixed rule and a complete dictionary let the extra 160 be created quickly and consistently.

One dictionary, one owner

The dictionary is small, two columns each of code and meaning, with one table for colours and one for specifications. Name one person to maintain it, and let only that person approve new codes. Keep it somewhere shared, so everyone who creates SKUs draws from it.

In the mapping table, give each SKU a row with columns for the marketplace code, supplier article number, barcode and notes, so the same SKU can be matched on the platform, in the books and in the warehouse.

If you already have a messy scheme

Do not change every old code overnight. A safer route:

1. From today, every new product follows the new rule.
2. Convert old products gradually. For each one, add an "old code" column in the mapping table so older documents can still be found.
3. Change the fastest sellers first, then the rest.
4. Avoid running a large count in the middle of the change, or count first and recode afterwards.

When codes change, update the marketplace code mapping and the internal labels too. Labels already printed and still in use keep their old code in the mapping table until they are replaced in the normal course.

InventoryHub builds the code mapping table with you and numbers and labels items that have none, handing over the labelling rules so that new products can follow the same scheme.