First: They Are NOT the Same Thing

Many business owners mix these up. They serve different purposes.

SKU — For You (Internal Use)

SKU (Stock Keeping Unit) is your internal product code.

• Created by you

• Used for inventory tracking

• Helps you manage variations (color, size, bundle)

• Can be letters, numbers, or both

Example:
TSHIRT-BLACK-M-01

📌 SKUs are not universal. Two businesses can have the same SKU—and that’s fine.

You always need SKUs, even if you sell only one product.

UPC — For Retail & Platforms

UPC (Universal Product Code) is the barcode used in retail and many online marketplaces.

• Usually 12 digits

• Scanned in stores

• Identifies a product globally

• Must be unique

If you plan to sell:

• On Amazon

• On Walmart

• In physical stores

• Through distributors

You’ll likely need a UPC.

📌 UPCs should come from an official source, not random generators.

GTIN — The “Parent” Code

GTIN (Global Trade Item Number) is the umbrella term.

It includes:

• UPC (12 digits – common in the US)

• EAN (13 digits – common internationally)

• ISBN (for books)

Platforms often ask for GTIN, but accept UPC or EAN as the actual number.

📌 Think of GTIN as the category, UPC as the format.

So… What Do You ACTUALLY Need?

Here’s the honest breakdown:

You need a SKU if:

• You manage inventory

• You sell more than one product or variation

➡️ This is non-negotiable.

You need a UPC / GTIN if:

• You sell on Amazon, Walmart, or major marketplaces

• You want brand protection

• You plan to scale or go retail

➡️ This is strongly recommended.

You may NOT need a UPC if:

• You sell only on your own website

• You offer handmade or custom products

• You sell digital products or services

But even then—having one helps future-proof your business.

Common Mistakes Business Owners Make

❌ Buying cheap UPCs from shady websites
❌ Using the same UPC for different products
❌ Not matching product data exactly across platforms
❌ Ignoring GTIN rules until listings get blocked

These mistakes can:

• Get listings suppressed

• Cause account issues

• Prevent brand registry approval

The Smart Way to Think About It

• SKU = internal control

• UPC / GTIN = external credibility

• Consistency = platform trust

Marketplaces trust businesses that look organized and legitimate.