How to Create SKU Codes: A Step-by-Step Guide for Growing Brands

Your SKU code is more than an identifier -- it is concise product shorthand that your team reads dozens of times a day. Well-structured SKU numbers make picking, packing, reordering, and reporting faster. Sloppy ones turn every warehouse scan and spreadsheet filter into a guessing game.

If you have been relying on random codes or manufacturer part numbers, this guide walks you through how to create SKU numbers that actually work -- from choosing your format to rolling them out across every sales channel.

How to Create SKU Numbers in 8 Steps

To create SKU numbers for your product catalog, follow these eight steps:

1. Understand what a SKU number does and how it differs from a UPC or barcode.
2. Define your SKU naming convention, including segment order, separator character, and abbreviation rules.
3. Choose a SKU number format structure that matches your product catalog.
4. Build an abbreviation library for colors, sizes, categories, and other attributes.
5. Assign SKU codes to every product in your existing catalog.
6. Set rules for creating SKU numbers for new products going forward.
7. Sync your SKU numbers across every sales channel and system.
8. Test, audit, and refine your SKU system after 30 days.

Step 1: Understand What a SKU Number Actually Does

Before you build anything, get clear on the job. A SKU (Stock Keeping Unit) is an internal alphanumeric code your business assigns to each distinct product variant. It is not a UPC or barcode -- those are external, universal identifiers. Your SKU belongs to you alone, and learning how to make SKU numbers correctly saves your team hours every week.

A good SKU number format tells your team three things at a glance:

• What the product is (category or type)
• Which variant this is (color, size, material, flavor)
• Where it fits in your catalog hierarchy

Here is a quick SKU number example: TSHIRT-BLU-M instantly tells a warehouse picker: cotton t-shirt, blue, medium. No lookup needed.

Step 2: Define Your SKU Naming Convention Before Creating a Single Code

This is where most teams go wrong. They start creating SKU codes one product at a time, making it up as they go. Six months later, the catalog is an inconsistent mess.

Define your SKU naming convention up front. Nail down these elements:

1. Segment order -- Which attribute comes first? Most brands use: Category - Attribute 1 - Attribute 2 - Sequence Number.
2. Separator character -- Dashes (-) are the most readable. Avoid spaces, slashes, and special characters.
3. Abbreviation rules -- Set a standard. Will blue be BLU, BL, or BLUE? Pick one approach and document it.
4. Character limit -- Keep SKUs between 8 and 16 characters. Long enough to be descriptive, short enough to scan quickly.

Write your convention in a shared doc. Everyone who touches product data should reference it.

Step 3: Choose Your SKU Number Format Structure

A SKU number format is the standardized structure a business uses to arrange product identifiers. The most common formats follow a pattern of category, attribute, and variant codes separated by dashes -- for example, TSHIRT-BLU-M for a blue medium t-shirt.

No single correct format exists, but the best ones share common patterns. Here are three proven structures you can adapt:

Format A: Category-Attribute-Attribute

Best for apparel, accessories, and consumer goods with clear variant dimensions.

Format B: Brand-Category-Variant-Sequence

Best for multi-brand retailers or distributors carrying overlapping product types.

Format C: Department-Category-Sequence

Best for businesses with broad catalogs (hardware, industrial supply, food service) where variants are less visual.

Each SKU number example above follows the same logic: start broad, get specific, keep it short. Pick the format that matches how your team thinks about products. If you sell apparel, Format A is the natural fit. If you resell multiple brands, Format B clears up confusion fast.

Step 4: Build Your Abbreviation Library

Once you pick your format, create a reference table of approved abbreviations. This prevents the number-one SKU problem: two people abbreviating the same thing differently.

Start with your most common attributes:

Colors:

Sizes:

Categories:

Keep this library in a shared spreadsheet or your inventory management system. Update it every time you add a new product line.

Step 5: Create SKU Codes for Your Existing Catalog

Now put your convention to work. Go through your current product list and assign SKU codes one batch at a time:

1. Export your full product catalog from your e-commerce platform or inventory system.
2. Sort by category so you can batch similar items together.
3. Apply your format to each product, pulling from your abbreviation library.
4. Check for duplicates -- every SKU must be unique. If two products generate the same code, add a sequence number (e.g., TSHIRT-BLU-M-01, TSHIRT-BLU-M-02) or refine your attributes.
5. Verify readability -- hand a list of 20 SKUs to someone on the warehouse floor. Can they identify the products without a lookup sheet? If not, rethink your abbreviations.

If you are working through a large catalog, an SKU generator tool can speed things up. It applies your naming rules automatically and catches duplicates before they become a problem.

Step 6: How to Make SKU Numbers for New Products

Creating SKU numbers for existing products is a one-time project. The real challenge is keeping things consistent as your catalog grows. Here is how to make SKU numbers for every new product without breaking your system:

Lock in these rules:

1. One person or team owns SKU creation. When anyone can make up codes, consistency falls apart within weeks.
2. New products follow the existing convention. No exceptions. No "temporary" codes.
3. New categories get added to the abbreviation library first -- before anyone creates SKUs in that category.
4. Retired products keep their SKUs. Never reuse a SKU code. Old order records, returns, and analytics all reference the original. Reusing creates data conflicts you will spend months untangling.
5. Review quarterly. As your product line evolves, confirm your naming convention still holds up. Extending a good system is easier than fixing a broken one.

Step 7: Sync Your SKU Numbers Across Every Channel

Your SKU system only works if it stays consistent everywhere. That means the same SKU shows up in your:

• E-commerce platform (Shopify, WooCommerce, BigCommerce)
• Marketplace listings (Amazon, Walmart, eBay)
• Warehouse management system
• Accounting and ERP software
• Purchase orders to suppliers

When SKU codes match across channels, inventory counts stay accurate, reorder points trigger correctly, and multi-channel reporting works without manual mapping.

If you manage this across three or more channels, a centralized inventory system is not optional -- it is the difference between controlled growth and firefighting every Monday morning.

For deeper guidance on keeping your SKU strategy clean as you scale, read 5 SKU Best Practices Every E-Commerce Brand Should Follow on the OmniOrders blog.

Step 8: Test, Audit, and Refine

Your first pass will not be perfect. Plan for that:

1. Warehouse test -- Have your fulfillment team work with the new SKUs for two weeks. Collect their feedback on readability and speed.
2. Search test -- Filter and search your catalog by SKU segments. Can you pull up all blue products? All t-shirts? All large sizes? If your format is solid, these filtered views should work without extra configuration.
3. Error audit -- After 30 days, check for mis-picks, mis-ships, and inventory discrepancies. Error patterns often trace back to confusing SKU similarities (e.g., BLU vs BLK under poor warehouse lighting).
4. Refine -- Adjust abbreviations, add sequence numbers, or extend your format based on what you find.

Steps to Create a SKU: Quick Summary

Here are the steps to create a SKU for any product in your catalog:

1. Define a naming convention with a consistent segment order and separator character.
2. Select a SKU format: Category-Attribute, Brand-Category-Variant, or Department-Category-Sequence.
3. Create an abbreviation library so every team member uses the same codes.
4. Assign SKU codes to your full product catalog, checking for duplicates.
5. Establish rules for generating SKUs for every new product added.
6. Sync SKUs across all sales channels, warehouse systems, and accounting software.
7. Audit your system after 30 days and refine based on error patterns.

Quick-Reference Checklist: How to Create SKU Numbers

Use this when you are ready to build or overhaul your system:

• Define your SKU naming convention and segment order
• Choose a consistent SKU number format (Category-Attribute or Brand-Category-Attribute)
• Build an abbreviation library for colors, sizes, and categories
• Assign SKU codes to your full existing catalog
• Check every code for uniqueness and readability
• Designate one owner for ongoing SKU creation
• Sync SKUs across all sales channels and systems
• Schedule quarterly reviews of your convention

Frequently Asked Questions About SKU Numbers

What Is a SKU Number?

A SKU (Stock Keeping Unit) number is an internal alphanumeric code that a business assigns to each distinct product variant. Unlike UPCs or barcodes, SKU numbers are unique to your company and encode product attributes like category, color, and size into a scannable, human-readable format.

What Is the Difference Between a SKU and a UPC?

A SKU is an internal code created by an individual business to track its own inventory. A UPC (Universal Product Code) is a standardized, externally assigned barcode used across all retailers. SKUs vary between companies, while UPCs remain the same everywhere a product is sold.

How Many Characters Should a SKU Number Have?

A SKU number should be between 8 and 16 characters. This range is long enough to encode meaningful product attributes like category, color, and size, but short enough for warehouse staff to read and scan quickly without errors.

Can Two Products Have the Same SKU?

No. Every SKU must be unique within your business. If two products generate the same SKU code, add a sequence number to differentiate them. Duplicate SKUs cause inventory count errors, mis-picks, and reporting conflicts across sales channels.

Should You Reuse SKU Numbers for Discontinued Products?

No. Never reuse a retired SKU number. Historical order records, returns, and analytics all reference the original SKU. Reusing a code creates data conflicts that can take months to untangle. Retired products should keep their SKU permanently.

Start Building Better SKU Numbers Today

A clear SKU system removes friction from every part of your operation -- from the warehouse floor to your monthly inventory reports. The time you invest now pays back every day your team touches product data.

If you run a multi-channel brand and want your SKU structure to stay consistent across every platform automatically, OmniOrders keeps your inventory, orders, and product data synced in one place -- so the system you built actually holds.