What Is a SKU Number: Examples (2026)

A stock keeping unit (SKU) number helps retailers identify and track products. Retailers rely on SKUs to retrieve purchases from the stockroom, organize merchandise, and sort items by factors such as price, color, and size.

For small businesses, SKUs streamline operations. Whether you run an ecommerce website with a massive inventory or a brick and mortar store with limited stock, assigning SKUs to products makes it easier to fulfill orders efficiently and provide a positive customer experience.

This guide covers what product SKUs are, how to create them, and how to manage them to organize your inventory.

What is a SKU number?

A stock keeping unit (SKU) number—pronounced “skew”—is a code retailers assign to a product or variant. It helps them track products, create inventory visibility, and analyze sales. SKU length varies by retailer and software.

Keep your SKUs as short as possible, a maximum of 16 characters. Every retailer creates its own SKU system. The details staff check first appear at the beginning of the code. Staff can then quickly identify and locate items. 

For example, an apparel retailer might use:

TSH-M-BLK-COT-001

• TSH = T-shirt (product category)
• M = medium (size)
• BLK = black (color)
• COT = cotton (fabric)
• 001 = running item number for uniqueness

Category and size appear first because staff often check those details when locating an item. Color and fabric follow. A short serial number makes the code unique. Floor staff can identify the product quickly. A POS system searches for products using the full SKU. 

SKUs are retailer-specific. The same product can have one SKU at one retailer and a different SKU at another. Retailers can also adapt their codes to meet vendor requirements and integrate with connected inventory management software.

Why are SKUs important for your business?

Inventory gets harder to manage as a catalog grows. A unique SKU separates one product or variant from every other item in the system. Their three main uses are:

• Inventory tracking. Track stock counts by item and location.
• Sales analytics. Compare sales by SKU to identify top sellers and slow-moving products.
• Quick replenishment. Monitor stock levels and reorder fast-selling items before they sell out.

Unique SKUs also make products easier to locate and orders faster to pick. Staff can search for an exact size or color without sorting through similar variants.

Consider a neighborhood bike shop that assigns a unique SKU to each tire tube size. When staff sell a tube through Shopify POS, the inventory count updates for that location. Managers can then review sell-through rates and days of inventory remaining to decide when to reorder popular sizes.

Accurate records are key to this process. A 2026 ECR Retail Loss report found that more than 60% of inventory records contain inaccuracies. Incorrect stock counts can delay inventory replenishment and create hidden stockouts because the system shows more inventory than is actually available.

Assigning every sale and stock adjustment to the correct SKU improves the data used for ordering and inventory counts. Retailers can also lower inventory costs by identifying slow-moving products before placing another purchase order.

Where to find SKU numbers

Here are common places where you can find SKU numbers:

• Product packaging. Flip any box or bottle over and you’ll spot a barcode label with the SKU printed nearby. 
• Receipts. When you sell a product, the receipt often lists the SKU number alongside the product description. 
• Price tags. Retailers often print SKU numbers on price tags, especially for products sold in-store.
• Inventory management systems. Your inventory management system (IMS) and POS system store SKU numbers for every product. 
• Product listings. Online retailers selling on Amazon or eBay typically include SKU numbers in the product details section of their listings.

Note that while SKU numbers and barcodes often appear adjacent to each other on price tags, they are not the same. A barcode is a format for encoding information—on a price tag. It usually represents the product’s Universal Product Code (UPC), which will be discussed later in this article. 

Where SKUs live in Shopify admin and POS

In Shopify, SKUs are stored at the product variant level. They can be added when creating a product or by editing existing products. Each product and each variant needs its own unique SKU.

In the Shopify admin, go to Products, open a product, then in the Variants section select a variant. In the variant’s Inventory section, click SKU to add or edit the SKU, then save. 

For larger catalogs, SKUs can be updated in bulk using the bulk editor or by importing via CSV.

In the Shopify mobile app, tap the price tag icon. Tap the product you want to edit. Open the Variants section, choose a variant, then edit the SKU in the Inventory section and save.

To find a product by SKU, enter the code in the Shopify admin search bar or the Shopify POS global search bar. Use the same letter case and spacing saved on the variant. In Shopify POS, select the matching result to view its details or add it to the cart.

How to create SKU numbers for products

Because stock-keeping units are designed for internal use, there are no hard rules when creating your own SKU system (also known as a SKU architecture). 

However, sticking to some basic conventions will help keep your SKU numbers compatible with external companies and software, should you need to work with a fulfillment partner.

Automated SKUs 

The easiest way to generate SKU numbers is by using an IMS or a POS system.

These SKU systems track customer orders and the status of organized stockroom goods. Most include an automated SKU code creation feature, meaning each product entered into your system automatically receives a unique number.

Assign product barcodes and SKUs with a Shopify app.

Manual SKUs

Store owners with small catalogs and few new product additions can create SKUs by hand. Store Leads’ 2026 State of Shopify report found that 782,386 Shopify stores, or 25.6%, sell one to nine products. Another 492,183 stores, or 16.1%, sell 10 to 24 products.

Manual SKU creation requires a consistent system for identifying each product’s main attributes:

• First characters identify the product category or supplier.
• Next characters identify details such as color, size, or brand.
• Final characters distinguish the product or variant from similar inventory.

Use codes staff can recognize, such as the first few letters of a supplier or brand name. Apply the same abbreviations across the catalog so each SKU follows the same structure.

Keep SKUs short so staff can read and enter them quickly. Check any character limits set by inventory software, marketplaces, or other connected systems.

A simple SKU schema template

The most practical way to build SKUs without a generator is to use an attributes-plus-sequence pattern. With a consistent format, every SKU is readable at a glance and still unique. It’s important to define your product taxonomy before creating SKUs so you know what information to communicate. 

Here is the standard template to use. Note that this can change depending on the type of business you run:

CAT-STYLE-COLOR-SIZE-SEQ

Here is what each means with examples:

• CAT: Category (TSH = t-shirt, SHO = shoes)
• STYLE: Style/model (SLIM, CREW, RUN)
• COLOR: Color code (BLK, WHT, RED)
• SIZE: Size or key variant attribute (M, 42, 250G)
• SEQ: Unique sequence (001, 002)

The template keeps your SKUs readable. Be sure to avoid special characters, symbols, and spaces. Keep SKUs as short as possible to stay compatible with your ecommerce platform. 

SKU examples by industry and product type

The three examples below show how store owners can build SKUs for different products.

Read a SKU from left to right. In LAP-HP-PRO-16-512-A1, LAP identifies the product category and HP identifies the brand. PRO names the model line. 

The next segments describe the product’s attributes. 16 means 16 gigabytes of RAM and 512 means 512 gigabytes of storage. The final segment, A1, is an internal batch code.

1. Electronics

LAP-HP-PRO-16-512-A1

• LAP = laptop
• HP = brand (HP)
• PRO = model line
• 16 = 16 GB RAM
• 512 = 512 GB SSD
• A1 = internal batch code

Gadget shoppers and sales reps care most about brand and specs, so the SKU highlights RAM and storage right after the model. The two-character batch code at the end lets you quickly track recall issues easily.

2. Books

BK-FIC-THR-JD-978055

• BK = book
• FIC = fiction (genre)
• THR = thriller (subgenre)
• JD = author initials (John Doe)
• 978055 = last six digits of ISBN

This SKU reflects how indie book shops shelve titles by genre first, followed by author. Borrowing a chunk of the ISBN prevents two thrillers by authors with the same initials from colliding in your system.

3. Coffee

COF-ARB-DK-250-003

• COF = coffee
• ARB = Arabica (bean)
• DK = dark roast
• 250 = 250-gram bag
• 003 = third roast batch of the day

Baristas can glance at the code to know bean type, roast, and pack size. The final three-digit batch counter helps them rotate stock before flavor peaks.

How to use SKUs to your advantage

Stores can use SKU data in six ways:

• Monitor trends and inventory levels
• Calculate reorder points
• Forecast demand and sales
• Plan product displays
• Upsell and cross-sell products
• Improve the customer experience

1. Monitor trends and inventory levels

Each product is assigned a unique SKU number, so it’s easy to track individual items. You can monitor products in detail, including variations like size, color, and style. 

SKU numbers enable accurate inventory reporting and barcode inventory management. Plus, SKU systems update inventory levels in real time as sales occur, providing consistently accurate stock data. You can anticipate future trends, evaluate sales (like which product variants are most and least popular), and optimize stock levels to prevent under- or overstocking.

Strong SKU organization also makes systems like perpetual inventory possible, saving you time and “fire drills” from high or low stock levels.

2. Calculate reorder points

Using SKU data, you can monitor product status and calculate reorder points—the inventory level that triggers an order for replacement stock.

Tracking how quickly each SKU sells helps determine when to reorder from suppliers. A study of 85 stores and 95 products found that automatic replenishment systems can reduce stockouts by up to 60%.

Shopify’s inventory management features automatically calculate reorder points based on supplier lead times, so popular SKUs can be reordered before they sell out.

3. Forecast demand and sales

Using a SKU system also improves the accuracy of sales and inventory forecasting. Run your SKU data through an ecommerce analytics tool to answer questions like:

• How much staff do I need on the shop floor during a specific season?
• What are appropriate inventory levels to prepare for weekends?
• How much payroll can my cash flow cover seasonally?

If your SKU data highlights low-selling items, you can monitor sales and reduce inventory accordingly. This ensures you meet customer demand without tying up cash in dead stock. 

For inventory planning and other ecommerce tasks, Shopify retailers have access to Sidekick, an AI-powered tool inside the admin. Pose questions like those above to Sidekick to create reports, build automations, or break down tasks based on your store data.

4. Plan product displays

SKU-level sales data reveals which products sell quickly and which sit longer. Stores can use that data to guide visual merchandising decisions. For example, you could move an underperforming high-margin item to eye level and compare sales before and after the change. 

An in-store experiment with potato chips found that the middle shelf generated the highest percentage of purchases. Ecommerce retailers can run a similar test by featuring the product in the homepage design, on a collection page, or simply above the fold on product pages.

5. Upsell and cross-sell products

Cross-selling tactics can help increase sales. SKU data can also be leveraged on the sales floor or within an ecommerce checkout.

For instance, SKUs enable cross-selling, upselling, and product recommendations. If a customer is purchasing a laptop, SKU data can automatically trigger your ecommerce site (or an in-store associate) to suggest compatible items like a laptop bag or wireless mouse, enhancing the customer’s shopping experience and increasing your sales.

If a product is out of stock, SKUs make it simple for retail staff or an online store’s AI agent to recommend similar products.

6. Improve the customer experience

Customer service teams use SKUs to identify the exact product or variant on an order. The code speeds up stock checks and gives staff the correct item reference for returns, exchanges, and product questions.

SKU-level records also improve the availability information presented to shoppers. In a field experiment with more than 840,000 Instacart customers, disclosing low-availability items reduced refunds by 3.7% and product replacements by 2.9%. Retailers can use current SKU data to reorder fast-selling items and reduce inventory risks.

Best practices for SKU management

These seven practices reduce coding errors and make SKU records easier to manage:

• Use a SKU management system
• Use one naming structure
• Train staff on how to use SKUs
• Avoid zeros or special characters
• Define popular product features
• Make regular SKU updates
• Use SKU data to improve sales

Use a SKU management system

A SKU management system is a place to store your SKU numbers and attach them to products. 

Shopify, for example, has a SKU field for each product listing—even supporting variant SKUs, like unique codes for each t-shirt size. This data is unified across your POS and ecommerce platform, allowing accurate inventory tracking and order fulfillment across multiple sales channels.

“I used to spend at least four hours manually counting inventory every month, and I always had to ensure our platforms were syncing up properly,” says Mandalyn Renicker, owner of Offbeat Bikes. 

“I don’t have to do that anymore, because Shopify’s inventory system is so robust and easy to manage. I’m flying through service invoicing at the end of each day faster than I ever could with Square, too, which I think is because the Shopify interface is just a lot easier to use.”

Use one naming structure

Keep your codes simple and understandable, and ensure your SKUs are created consistently across your entire product catalog. 

Implement a logical hierarchy in your SKUs for easy organization. This means using a consistent structure and format, making it clear to understand for inventory management purposes.

Train staff on how to use SKUs

Retail employees interact with SKUs daily. Include them when creating new SKU numbers or discontinuing products to train them on your SKU management processes. For example, do they know that “EV” is code for supplier Eastern Vines? 

Keep employee training going after onboarding with simple, low-stress methods or short, incentivized quizzes.

Avoid zeros or special characters

Zeros can be skipped by some retail software or mistaken by employees for the letter O, causing confusion when inputting SKUs.

Similarly, special characters, such as !, @, or &, can disrupt certain software systems, so avoid them in SKU codes.

Define popular product features

Help your sales team by using SKU numbers to highlight popular product features. For example, if you’re a clothing retailer, you might notice certain colors, sizes, or styles sell better than others. By using SKU numbers to track these attributes, you can better understand customer preferences and adjust your inventory accordingly.

Tracking these attributes with SKUs ensures you’re stocking the right mix of products to meet customer demand.

Make regular SKU updates

As your product offerings change, so should your SKUs. Update SKUs when introducing new product features or discontinuing products.

Use SKU data to improve sales

Use SKU data to make business decisions. For example, you can use SKU sales data to determine which products to promote or discount, or inventory data to calculate reorder points and avoid stockouts.

You can also track SKUs to monitor sales trends and inventory levels. Doing so provides valuable insights into which products sell well and which ones don’t, helping you make informed inventory management decisions.

Advanced SKU strategies for growing businesses 

Business growth adds three areas to SKU management:

• SKU analytics
• SKU automation
• International selling

SKU analytics

Run SKU data through a business intelligence (BI) tool to understand profitability metrics across different product lines and allocate inventory more effectively. 

A European chain used AI-powered SKU rationalization to eliminate 200 low-yield items, resulting in an additional €30 million in margin within one season.

For another example, if Store A sells 15 red hoodies a day but Store B moves only two, SKU analytics flags the imbalance so you can transfer surplus inventory instead of placing a new purchase order.

You can pull SKU-level data from your store with Shopify Sidekick AI questions like:

• What are the gross margins per SKU for the past 90 days?
• Which SKUs have an annual turnover rate below two but tie up more than $5,000 in inventory?
• Show me a list of SKUs for which the days of supply exceed the lead time by 50% or more.

Discontinue SKUs that aren’t selling, and reinvest in the ones that drive most of your profit margin. 

SKU automation

Automated inventory management is key for scaling brands. Some ways to automate your SKU processes include:

• Use templates to generate SKUs. Apply logical attributes (for example, CAT-SIZE-COLOR-SEQ) so software can assemble SKUs on the fly when a new variant drops.
• Trigger life cycle updates. Automatically update SKU status (inactive, end of life) when sell-through falls below a threshold. 
• Maintain version control. Lock SKU edits behind role-based permissions. Keep a “do not reuse” list so retired codes don’t reappear in your system.

International selling

The moment you ship across a border, poor SKU management gets expensive fast. Incorrect classification and documentation can cause costly delays.

With the end of the US duty-free de minimis exemption for parcels from China and Hong Kong in May 2025, every shipment now needs a full tariff classification and duties paid upfront. Building globally consistent SKUs tied to GS1 GTINs, HS codes, and accurate descriptions ensures parcels move efficiently.

Shopify Managed Markets integrates this entire workflow directly into your admin. Managed Markets acts as a merchant-of-record service, automatically attaching HS codes, collecting and remitting duties and taxes at checkout, and printing compliant customs forms.

Common SKU mistakes to avoid

Many SKU errors begin when teams use different naming rules. Watch for these common problems and consider the suggested actions to prevent them:

• Inconsistent naming conventions. Department-specific patterns make SKUs harder to read and search. 

Action: Use one structure, such as Category-Style-Size, across the catalog.

• Using meaningless codes. Random strings require staff to memorize lookups. 

Action: Use recognizable abbreviations for attributes such as product type, color, or size.

• Reusing a SKU. Shopify displays a warning in the Inventory section when it detects a duplicate SKU. Duplicate codes can affect inventory tracking and third-party integrations.

Action: Assign each product and variant a unique SKU unless a bundle or another workflow requires a duplicate.

• Making SKUs too long or too short. A short code may lack the detail needed for accurate inventory reporting. A long code takes more time to read and enter. 

Action: Keep SKUs concise and check the limits of connected systems.

• Failing to review SKUs. Catalog changes can create duplicate or conflicting codes. 

Action: Schedule audits to retire outdated SKUs and keep new products aligned with the established system.

• Confusing SKUs with other product codes. SKUs track internal stock. UPCs and EANs identify products across businesses, while barcodes present codes in a scannable image. 

Action: Keep each identifier in its designated field.

SKUs vs. other retail codes

SKU numbers aren’t the only product codes retailers use. Here’s how to distinguish them from each other.

SKU vs. UPC code

Retailers use both SKUs and UPCs simultaneously, but they are not the same. SKUs are for internal tracking needs, and UPCs are universal. 

UPCs, or Universal Product Codes, are another widespread form of product identification. SKUs and UPCs look similar and are used simultaneously by retailers, but their functions differ slightly. 

A stock-keeping unit identifies a unique product and its traits, while a Universal Product Code represents a product’s manufacturer (the first six numbers) and its item number (the next five digits). UPC codes also contain a check digit (the last number), serving as a validation mechanism.

Here’s a helpful breakdown of the differences between SKUs and UPCs:

SKU vs. GTIN codes

A Global Trade Item Number (GTIN) is a globally unique product identifier governed by GS1 standards. GTINs contain 8, 12, 13, or 14 digits. The brand owner assigns a GTIN to each product and packaging level.

SKUs identify products within a retailer’s inventory system. GTINs identify the same product across retailers and supply chain partners. A UPC-A barcode, for example, encodes a 12-digit GTIN.

Products purchased for resale may already have a GTIN assigned by the brand owner. The number often appears beneath the barcode on the product’s packaging or other physical inventory.

SKU vs. barcode

A barcode is the batch of black lines found on product labels or packaging, which retailers scan when completing a customer’s purchase. The term “barcode” is often used interchangeably with “UPC,” because most barcodes encode UPC numbers.

Unlike SKU numbers, when retail stores generate a barcode, they don’t create a new UPC. Barcodes are assigned to all identical products, regardless of where they are sold. However, retailers may print product labels that include both a UPC barcode and their store’s SKU number.

SKU vs. serial number

A serial number tracks products for warranty claims, repairs, and recalls. They are used by manufacturers to track product batches and identify defective units. Serial numbers are different from SKUs because they’re unique to each individual unit. Conversely, multiple identical units share the same SKUs.

SKU vs. ASIN

An ASIN (Amazon Standard Identification Number) is a 10-character identifier assigned by Amazon. Each Amazon listing product has a unique ASIN, which helps Amazon keep track of products in its ecommerce catalog and optimize pages for search.