What Is a SKU? SKU vs Article Number vs Barcode, and How to Manage Thousands of Products

Short answer: A SKU (Stock Keeping Unit) is an internal code a business assigns to each distinct product variant it stocks, such as "red T-shirt, size M". An article number usually identifies the manufacturer's model, while a barcode (EAN/UPC) lets any scanner in the world recognise the item. The SKU is the unit your own warehouse, sales and analytics run on: stock levels, turnover and margin are all measured per SKU.

With a small range, everything fits in someone's head or a spreadsheet. Once you carry hundreds of items, the questions start: how many do we have left, which size sells fastest, why has this item sat on the shelf for six months? Every one of those answers depends on a well-designed SKU system. This guide explains what a SKU is, how it differs from an article number and a barcode, how to structure SKU codes, and how to run thousands of SKUs in an ERP system.

What does SKU mean?

A SKU is an internal stock code that distinguishes one sellable variant from every other. The letters stand for Stock Keeping Unit, and the term is used across retail, wholesale, e-commerce and manufacturing.

The crucial point is that a SKU belongs to a specific variant, not to a product in general. If one sneaker model comes in 5 sizes and 3 colours, that is 15 separate SKUs. To your warehouse, black size 42 and white size 43 are different stock, different sales and different purchase orders.

What a SKU does for you:

• Accurate stock counts for every variant on hand.
• Fewer picking and shipping errors, because staff pick a precise code rather than "the blue shirt".
• Sales analytics that show which variants earn money and which have turned into dead stock.
• Purchase planning, since you can see in advance which items are running out.
• A shared language between systems: store, warehouse, accounting and marketplace all refer to the same code.

Each company designs its own SKUs, so the same product can carry different SKUs in two different shops. That is normal and expected.

What is the difference between a SKU, an article number and a barcode?

In short: an article number identifies a model, a SKU is your internal variant code, a barcode (EAN/UPC) is a global number for scanners, and serial and lot numbers track an individual unit or a production batch. These terms get mixed up constantly, especially in markets where "article" (artikul) is used loosely for any product code.

• SKU — Assigned by: Your company; Identifies: A specific variant (colour, size, pack); Example: TSH-RED-M; Used in: Warehouse, sales, analytics, ERP
• Article number — Assigned by: Usually the manufacturer or supplier; Identifies: A model or product type; Example: AX-2045; Used in: Catalogues, supplier communication
• EAN-13 — Assigned by: Manufacturer via GS1; Identifies: A global trade item number (13 digits); Example: 4780000000000; Used in: Checkout scanners, retail
• UPC-A — Assigned by: GS1 (mainly US and Canada); Identifies: A global trade item number (12 digits); Example: 012345678905; Used in: North American retail
• Serial number — Assigned by: Manufacturer; Identifies: One individual unit; Example: SN-8F21K0093; Used in: Warranty, electronics, equipment
• Lot / batch number — Assigned by: Manufacturer; Identifies: Units produced together; Example: LOT-2609-A; Used in: Food, pharmaceuticals, chemicals

SKU vs article number: an example

A supplier ships you a shirt with article number AX-2045. The model comes in 3 colours and 4 sizes. There is one article number, but in your warehouse there are 12 SKUs: SHR-AX2045-WHT-S, SHR-AX2045-WHT-M and so on. One article number can sit above many SKUs.

SKU vs UPC: can a barcode replace a SKU?

Only partly. EAN and UPC codes are also assigned per variant, but:

• they are strings of digits that tell a person nothing about the product;
• they do not always exist, for example on goods you manufacture or repack yourself;
• the same item bought from different suppliers can carry different barcodes.

Best practice is to keep both: the SKU for internal management and the barcode for scanning and checkout. In an ERP, the product record has a field for each.

How do you create a SKU?

A good SKU is short, logical, unique and readable at a glance. It is usually built from a few segments: category, brand or model, then the attributes that define the variant, such as colour, size or volume.

A general pattern: [Category]-[Brand/Model]-[Attribute 1]-[Attribute 2]

Step by step: designing a SKU system

1. Define your categories. Two- to four-letter abbreviations are enough: TSH (T-shirts), CEM (cement), FLT (filters).
2. Decide which attributes create a variant. In apparel it is colour and size; in building materials, grade and pack weight; in auto parts, the vehicle model and part type.
3. Set the order of segments, from general to specific.
4. Write an abbreviation dictionary (RED = red, BLK = black, and so on) and keep it as a shared document.
5. Limit the length. Eight to sixteen characters works well in practice.
6. Enforce the rules in your ERP so the system itself blocks duplicates.

SKU number examples: apparel, building materials, auto parts

• Apparel — Product: Men's T-shirt, red, M; Example SKU: TSH-MEN-RED-M; Structure: category – gender – colour – size
• Apparel — Product: Jeans, blue, 32/34; Example SKU: JNS-BLU-3234; Structure: category – colour – size
• Building materials — Product: Cement M400, 50 kg bag; Example SKU: CEM-M400-50; Structure: category – grade – weight
• Building materials — Product: Plasterboard 12.5 mm, moisture-resistant; Example SKU: GYP-125-MR; Structure: category – thickness – type
• Auto parts — Product: Oil filter, Chevrolet Cobalt; Example SKU: FLT-OIL-CBL; Structure: category – type – model
• Auto parts — Product: Front brake pads, Nexia 3; Example SKU: BRK-FRT-NX3; Structure: category – position – model

Notice what is missing: price, supplier name and dates. Anything that can change belongs in other fields of the product record, not in the code.

What are the most common SKU mistakes?

The biggest mistake is letting SKUs grow without rules, with each employee inventing codes their own way. The result is one product living under two codes, two products sharing one code, and stock records that no longer add up.

Other frequent mistakes:

• Leading zeros. Excel quietly turns 0123 into 123, and imports stop matching.
• Look-alike characters such as O and 0, or I and 1, which cause errors when codes are typed by hand.
• Spaces and special characters (/, *, #), which some systems and marketplaces reject.
• Codes that are too long to fit on a label or to read aloud.
• Using the supplier's article number as your SKU. Change suppliers and your whole structure breaks.
• Reusing retired SKUs. Historical reports become wrong. Archive the old code and give the new product a new one.
• Meaningless sequential numbers (00001, 00002). They work, but nobody can tell what the item is from the code.

These problems hurt most when a business moves from spreadsheets to an ERP. We cover that transition in moving from Excel to ERP: why and when.

How are SKUs used in inventory analytics?

The SKU is the smallest unit of inventory analysis: stock, turnover, margin and dead stock are all measured per SKU. Totals for a whole category hide a lot, while SKU-level data shows exactly where the problem sits.

ABC and XYZ analysis

• ABC analysis ranks SKUs by their contribution to revenue: A is the small group that brings most of the revenue, B is the middle, and C is the long tail of many low-contribution items.
• XYZ analysis measures how stable demand is: X sells steadily, Y fluctuates or is seasonal, and Z is unpredictable.

Combine the two and you get a nine-cell matrix. SKUs in the AX cell should never run out, while CZ items are candidates for removal from the range.

Turnover and dead stock

• Inventory turnover shows how many days a SKU sits in the warehouse on average. Slow movers tie up working capital.
• Dead stock is any SKU with no sales over a chosen period, such as 90 or 180 days. Finding it requires a last-sale date for every SKU.
• Minimum stock and automatic replenishment set a minimum and maximum per SKU, and the system proposes purchase orders.

Doing this by hand in a spreadsheet is hard with a hundred items and practically impossible with thousands. See how an ERP handles it in Odoo Inventory: digitising warehouse management.

How do SKUs work on marketplaces?

On marketplaces such as Uzum Market or Wildberries, the seller links its own SKU (the seller article) to each listing, and the platform assigns its own internal ID. Orders, stock and settlement reports are matched through these codes.

Practical advice:

• Use the same SKU in your warehouse and on every marketplace, or you will reconcile orders by hand.
• Give each variant its own SKU and barcode. Platforms generally expect a separate barcode for each size and colour.
• Synchronise stock. If an item sells both in-store and online, stock must be kept in one place, or you will accept orders for goods you no longer have.
• Check the code format. Each platform has its own rules on allowed characters and length, so verify its current requirements.

How do you manage thousands of SKUs in an ERP like Odoo?

In Odoo, each product template is split into variants through attributes, and every variant gets its own SKU (the Internal Reference field), barcode, price and stock level. This lets you manage thousands of SKUs by rules rather than by hand.

Key Odoo capabilities:

• Attributes and variants. Create "Colour" and "Size" once, attach them to a product, and Odoo generates every combination. Combinations you do not sell can be excluded.
• Internal Reference, the SKU field, used in search, reports and imports.
• Barcode field for EAN/UPC or internal barcodes, working with Point of Sale and warehouse scanners.
• Serial and lot tracking: serials for equipment, lots and expiry dates for food and chemicals.
• Multiple warehouses and locations, showing which warehouse and shelf holds each SKU.
• Reordering rules that propose purchases when stock hits the minimum.
• Bulk import of thousands of SKUs from Excel or CSV in one go.

Odoo is an open-source ERP developed in Belgium, and the official description of its inventory app is on odoo.com. The same product record is shared by Sales, Purchase and Point of Sale, so a SKU means the same thing everywhere.

Timsoll case: 7,000+ SKUs in one system

Wholesale company Timsoll manages more than 7,000 SKUs in Odoo. At that scale, tracking stock, prices and orders in spreadsheets is practically impossible, while the ERP gives one accurate record for every item. Read how the project was delivered: Timsoll: how Odoo ERP manages 7,000 SKUs.

What should businesses in Uzbekistan know about SKUs?

In Uzbekistan, a SKU system is more than an internal convenience: it has to fit electronic invoicing, VAT (QQS) accounting and mandatory digital marking. Several local factors matter.

• E-invoices and tax. Line items on electronic invoices should match the items in your stock records. When product records and SKUs are set up properly, those documents are far easier to generate from the ERP. For local tax setup, see Odoo tax and VAT localisation for Uzbekistan.
• Digital marking (Asl belgisi). Uzbekistan has introduced mandatory digital marking for a number of product groups. A marking code is assigned to each individual unit and does not replace the SKU; it complements it. The SKU works at variant level and the marking code at unit level. Check official sources for which groups are covered.
• Legacy 1C catalogues. Many companies have product lists that grew in 1C for years without rules: duplicates, identical names, inactive items. Moving to an ERP is the best moment to clean up. For a comparison, read Odoo vs 1C.
• Many sales channels. Bazaar stalls, shops, Telegram sales and marketplaces often run in parallel, and without one SKU master list stock figures drift apart quickly.
• Two languages. Product names are usually kept in Uzbek and Russian, while a SKU is language-neutral and works the same in both.

How Deep Vision can help

Deep Vision is an Odoo Gold Partner in Tashkent, and we handle the whole path from cleaning up your product catalogue to running thousands of SKUs in Odoo. Our team includes 7 certified Odoo specialists, and 26 of our client projects are listed in the Odoo partner catalogue (official partner page).

How we work:

1. Business diagnostics and process analysis: we review your current catalogue, codes and warehouse processes.
2. Configuration and customisation: SKU rules, attributes, variants, barcodes and warehouse structure.
3. Integrations with tills, scanners, marketplaces and other systems.
4. Data migration from Excel or 1C, cleaned and free of duplicates.
5. Staff training, plus support after go-live.

A typical project takes 2–6 months, and standard Sales and Inventory modules can be running in 6–8 weeks. Uzbekistan localisation (invoices, VAT rates, reporting) is included. Our experience covers trade (Optika.uz, Timsoll), manufacturing (RockBeton), construction and services. Learn more about our Odoo implementation service.

Ready to bring order to your catalogue? Fill in the free brief or call +998 77 093 00 07. We reply within 24 hours.

Frequently asked questions

What is a SKU in simple terms?

A SKU is an internal code a company gives to each product variant it stocks. The letters stand for Stock Keeping Unit. For example, every colour and size of the same T-shirt is a separate SKU.

What is the difference between a SKU and an article number?

An article number is usually assigned by the manufacturer or supplier and identifies a model. A SKU is created by your own company for a specific variant. One article number can cover several SKUs.

Is a SKU the same as a UPC or barcode?

No. A barcode (EAN-13 or UPC) is a global number designed for scanners, while a SKU is a human-readable internal code. Best practice is to keep both on the same product record.

How long should a SKU be?

There is no single standard, but 8–16 characters works well in practice. The code should fit on a label, be easy to read and avoid spaces and special characters. Marketplaces may set their own limits, so check their requirements.

Does a small shop need SKUs?

Yes, if your products come in variants by colour, size or pack, SKUs are useful even with a few dozen items. They show exact stock levels and which variants sell best. As the range grows, stock-keeping without SKUs quickly becomes chaotic.

Where is the SKU stored in Odoo?

In Odoo, the SKU lives in the "Internal Reference" field of the product record. For products with variants, each variant has its own internal reference and barcode. The code is used in search, reports, imports and Point of Sale.

Can a digital marking code replace a SKU?

No, they work at different levels. A SKU identifies a product variant, while a marking code tracks each individual unit. In an ERP the two are used together.

How do you manage thousands of SKUs?

Thousands of SKUs need an ERP: variants generated from attributes, bulk import, reordering rules and ABC/XYZ analysis. For example, Timsoll manages more than 7,000 SKUs in Odoo. At that scale, spreadsheets lead to errors and lost time.

Conclusion

A SKU looks like a small detail, yet it underpins all product and inventory management. A well-designed SKU system shows accurate stock, makes analytics possible and simplifies work with marketplaces and tax documents. Once you have hundreds or thousands of items, SKUs belong in an ERP. If you want to clean up your catalogue and move to Odoo, book a free consultation or call +998 77 093 00 07.