What Is a SKU Number? a Simple Guide for SA Makers
July 9, 2026 · 13 min read · Chris Edington
A SKU, or Stock Keeping Unit, is your own private, unique code for each product you sell, helping you keep your stock organised. It's usually 8 to 12 characters long, and each product variation needs its own code, so a t-shirt sold in 5 colours and 3 sizes creates exactly 15 unique SKUs.
If you're starting an online shop in South Africa, this matters sooner than anticipated. One week you're making earrings at the kitchen table or packing candles from a spare room. A few orders later, you're digging through boxes for the rose-gold pair, sending the wrong size tee, or wondering whether you've already sold the last navy item on Instagram, WhatsApp, or your site.
That's where a simple SKU system helps. You don't need fancy software language or a big retail setup. You just need a naming system that makes sense to you, your products, and the way you pack orders every day.
Table of Contents
- Feeling Lost in Your Stock Room
- What a SKU Number Is and How It Works
- The Difference Between SKUs and Barcodes
- Why Your Small Business Needs SKUs
- A Simple Way to Create Your Own SKU Numbers
- Adding SKUs to Your Shopstar Products
Feeling Lost in Your Stock Room
Lindiwe started with handmade necklaces. At first, keeping stock in her head worked fine. She had a few silver pieces, a few beaded styles, and one tray for custom orders. Then orders picked up.
Soon she had gold, silver, and rose-gold versions. Short chains, long chains, gift-boxed sets, and custom initials. One Friday afternoon, she packed the wrong colour necklace for a customer in Johannesburg and spent the evening fixing the mistake instead of making new stock.
That kind of mess doesn't mean you're bad at business. It usually means your business is growing.
When your products start multiplying
The moment you sell variations, things get tricky. A blue candle isn't the same as a white one. A size small tee isn't the same as a size medium. A boxed item also isn't the same as an unboxed one when you need to ship it.
A simple code for each item brings calm to that mess. Consider a library shelf system. Books don't get piled randomly. Each one gets a code so the librarian can find the exact copy fast. Your products need the same treatment.
Practical rule: If you've ever said, “I know it's here somewhere,” you're ready for SKUs.
A small system that saves big stress
You can create this system yourself with a notebook, spreadsheet, or product dashboard. It doesn't have to be complicated. The point is to make every item easy to spot, count, pack, and reorder.
If you also want broader help with optimising inventory control strategies, that can give you a useful next step once your naming system is in place. And if you're still getting your head around packing and dispatch, this guide to how fulfilment works for online stores helps connect your product codes to the actual job of getting orders out the door.
What a SKU Number Is and How It Works
A SKU number is a unique code you create for one specific product version in your shop. It's for your own use. Not the public. Not the supplier. Not the shopping mall shelf. Just your business.
The full name, Stock Keeping Unit, sounds more technical than it is.
- Stock means the items you sell.
- Keeping means tracking and managing them.
- Unit means one specific version of a product.
Think like a library
A library doesn't label every book “book”. It gives each one a specific code so staff can find the exact title, edition, and place on the shelf. A SKU does the same for your online store.
If you sell a plain black mug and a plain white mug, those are not one product for stock purposes. They're two separate items because they can sell out separately.
One variation equals one SKU
This is the part that catches beginners. A product name and a SKU are not the same thing.
According to this guide on how SKU counts grow, a SKU is a unique alphanumeric code, typically 8 to 12 characters long, assigned internally to track each distinct product variant. It also gives a clear example. If a t-shirt is sold in 5 colours and 3 sizes, that creates exactly 15 unique SKUs.
Here's that idea in plain language:
| Product | Variations | Result |
|---|---|---|
| T-shirt | 5 colours × 3 sizes | 15 unique SKUs |
| Candle | 2 scents × 2 sizes | 4 unique SKUs |
| Necklace | 3 finishes × 2 chain lengths | 6 unique SKUs |
That's why “I sell one necklace” often turns into several stock lines very quickly.
What the code usually looks like
A SKU can contain letters and numbers. Many sellers make the code descriptive so they can read it at a glance.
For example:
- NEC-SLV-001
- TEE-BLU-MED
- CAN-VAN-LRG
You don't need the perfect system on day one. You need a system that's clear, repeatable, and easy to read when you're tired and packing orders late at night.
A good SKU answers one simple question fast. “Which exact item is this?”
The Difference Between SKUs and Barcodes
A common point of confusion for new sellers arises. They hear “product code” and assume all codes do the same job. They don't.
A SKU is your shop's private language. A barcode such as a UPC or EAN is a public language used across retail and supply chains.
Your code versus a shared code
You create your own SKU. It reflects how you sell products.
A barcode is different. That code is meant for wider use outside your business, especially when products need standard identification across stores or marketplaces.
An easy way to grasp this is:
| SKU | Barcode |
|---|---|
| You create it | It follows a wider standard |
| Used inside your business | Used outside your business too |
| Can include letters and numbers | Commonly used as a scannable retail code |
| Helps you track stock | Helps identify products across systems |
Why this mix-up costs local sellers money
For South African makers, this confusion isn't just a wording problem. It affects listings, shipping, and admin.
A 2025 Stats SA SME survey discussed in this SKU vs UPC article found that 82% of South African small businesses report inventory tracking issues, while only 14% correctly distinguish SKU from UPC in practice. That tells you how common this mistake is.
If you treat a SKU like a barcode, you can build the wrong system from the start.
The simple way to remember it
Use this test:
- If the code is for your own stock control, it's a SKU.
- If the code is for broader retail identification, it's a barcode system such as UPC or EAN.
That matters if you plan to sell handmade jewellery, clothing, candles, skincare, or gift boxes online. You still need your own internal naming system, even if a platform or retail partner asks for another code later.
Why Your Small Business Needs SKUs
Many beginners think SKUs are only for big shops with warehouses. They're not. They help the most when your business is still small enough for mistakes to hurt.
A missing item, a wrong parcel, or an undercharged courier fee can wipe out profit on a single order. A simple SKU system gives you a cleaner way to work day by day.
They make daily selling easier
When every item has a clear code, you can answer basic business questions faster.
- What's in stock: You can see whether the blue earrings are still available.
- What sold out: You don't need to search three boxes and a WhatsApp chat.
- What to pack: A code reduces mix-ups between similar items.
- What to remake: Your bestsellers become easier to spot.
That's especially useful if you sell in more than one place, like your online shop, markets, Instagram, and direct messages.
They also affect shipping money
In South African logistics, a SKU isn't only a label. It also acts like a small data record tied to the product. According to Fulfillment South Africa's guide to SKU measurement, each SKU needs precise weight and dimensions, entered in kilograms to 0.001 kg accuracy and centimetres to 0.1 cm accuracy, for automated shipping calculations and smart stock location logic.
If that data is wrong, your shipping fee can be wrong too.
- Too low: You absorb the extra courier cost.
- Too high: The customer pays too much and may abandon the sale.
- Wrong packaging flag: You may pay for unnecessary extra boxing.
Good SKU data helps protect your margin before the parcel even leaves your hands.
They help you build better habits
You don't need a giant stockroom to benefit from structure. Even a shelf in a garage or a few plastic bins in a spare room runs better when each product variation has a clear identity.
If you want to learn to manage inventory with more discipline, it helps to start with naming first. Once your SKUs are clear, counting, storing, and reordering become much easier to manage.
A Simple Way to Create Your Own SKU Numbers
You don't need a complicated formula. You need one that you can repeat without thinking too hard.
A strong SKU structure in retail is typically 8 to 12 characters long. The first 2 to 3 characters identify a top-level category, then you add product attributes such as colour or size, and finish with a sequential number like 001 or 002, as explained in this guide to building robust SKU numbers. The same source also notes that SKUs should stay distinct from UPCs and should avoid special characters or leading zeros.
A simple formula for handmade products
Start with this:
Category + Attribute + Attribute + Number
For many South African makers, that's enough.
A useful local approach is to begin with a top-level product marker such as JWL for jewellery or BRN for branch-style grouping, then add details and end with a sequence number, as described in this practical SKU naming article for ecommerce businesses.
Real examples you can copy
Here are three starter formats:
-
Jewellery:
JWL-SLV-001
This could mean jewellery, silver, item 001. -
Candles:
CAN-VAN-001
This could mean candle, vanilla, item 001. -
Clothing:
TEE-BLU-001
This could mean t-shirt, blue, item 001.
If your store has variants, you can expand the middle part. If you'd like help setting up those options on your product pages, this guide to selling product variants is useful.
Here's a short walkthrough before you build your own:
Rules that keep the system clean
Keep these habits from the start:
- Use CAPITAL letters: They're easier to scan quickly.
-
Use numbers at the end:
001,002,003keeps items in order. - Keep it readable: Short chunks help when you're packing.
- Avoid special characters: Don't use symbols that confuse systems.
- Don't copy barcode logic: Your SKU is for your internal setup.
A separate guide for South African sellers notes that SKUs are created in-house by each retailer, are not universal like UPCs, and should avoid special characters such as & or %, while keeping letters in capitals and numerals in a consistent format in inventory software used across channels in South Africa, as explained in this Shopify article on SKU numbers.
Keep this test in mind: if you can read the code in two seconds and know what item it refers to, you're on the right track.
Adding SKUs to Your Shopstar Products
Once you've created your SKU naming pattern, the next part is simple. Add that code to each product and each variant in your store dashboard.
If you're editing a necklace with different finishes or a t-shirt with multiple sizes, each version should get its own SKU. That gives your store a clean way to tell one item from another.
Where to place the SKU
When you add a new product or edit an existing one, look for the product details or variant area where stock information is managed.
You'll want to enter the SKU carefully and keep the same naming style across your whole catalogue. If you're managing stock per product or per variant, this help guide for inventory management settings shows where those controls sit.
Small details matter here
A practical rule from ecommerce operations is that SKUs are created by each retailer for their own product list, and they should avoid characters like & or %, while using CAPITAL letters and numerals 0–9 consistently across systems, as explained in the Shopify source linked earlier.
That means a clean entry such as JWL-SLV-001 is safer than a messy version like jwl&silver%1.
Use one naming style. Stick with it. That's what turns a simple code into a dependable stock system.
If you're ready to turn your handmade products into a proper online store, Shopstar gives South African makers a simple way to set up products, variants, stock, payments, shipping, and orders in one place. It's built locally for creators who want to start small, stay organised, and grow with confidence.
