What is a Product Identifier and What Are They Used for?

Working in product management and e-commerce logistics, I’ve seen firsthand how product identifiers are at the center of almost everything we do.

They are essential for managing inventory, ensuring correct barcode labeling, entering global markets, fighting counterfeits, and staying compliant with regulations.

It is surprising how many businesses still overlook or underestimate the importance of these unique codes.

Below, I break down what a product identifier is, how it works, and why it is so important for competing in a tough market, whether you sell in physical stores or online.

Defining a Product Identifier in Plain Terms

A product identifier is a unique code or number that points to a specific product. Think of it as a digital or numeric fingerprint that the product carries, making it easy to distinguish from every other item.

Most of the time, product identifiers come as numerical or alphanumeric sequences—like “12345ABC”—that a business or an industry group assigns for quick scanning and lookups.

Those barcodes on product packaging almost always refer to a product identifier in the background.

I always say: If your products cannot be identified uniquely, managing them effectively becomes impossible.

Why Do Product Identifiers Matter So Much?

I often hear questions from people who assume they can rely on brand or product names alone. For example, if “Brand XYZ Pro Headset” differentiates itself from “Brand XYZ Basic Headset,” is there truly a need for formal identifiers?

Yes. Here is why:

1. Precision and Clarity: Product names can change and new variants can emerge. A unique code assigned to a product stays consistent.
2. Automation Benefits: Automated systems depend on structured data. Your ERP, checkout system, or online platform uses the product identifier for tasks like order processing and inventory tracking, eliminating guesswork.
3. Global Consistency: Today, it is not enough to be recognized locally. If you need to list your product internationally, the same identifier helps in maintaining uniformity.

Real-Life Example: The Time I Shipped the Wrong Item

I remember working on a small e-commerce project for a friend who sold phone accessories. We tried managing inventory manually—naming each phone case ourselves. This led to several orders being sent out incorrectly because the variant names were too similar.

We ended up sending an iPhone 13 Pro case to a customer who had ordered an iPhone 13 mini case. There was also a color variation problem, which resulted in a complete return-and-exchange mess.

Had we assigned proper Stock Keeping Units (SKUs) and tracked them systematically, we could have avoided the entire mix-up.

Common Types of Product Identifiers

There isn’t just one universal type of product identifier—there are several, and sometimes they overlap while serving different needs.

Before we get into them, here is a quick overview of what they should look like in a real feed (if you need a deeper look you can always see googles sample feed):

      <products>
                <product>
                    <product_ids>
                        <gtins>
                            <gtin>541710238425</gtin>
                        </gtins>
                        <mpns>
                            <mpn>60101-10000</mpn>
                        </mpns>
                        <skus>
                            <sku>6206</sku>
                        </skus>

Here are the main ones:

1. Global Trade Item Number (GTIN)

Whenever I hear global trade item number (GTIN), I think of the standard that keeps international trade running smoothly. GTINs are used worldwide to identify trade items, whether they are sold in a physical store, a hospital, or an online marketplace.

They serve two main tasks:

• They are embedded in barcodes that get scanned at checkout counters or distribution centers.
• In online systems, GTINs often form the backbone for accurate product listings and order fulfillment.

2. Stock Keeping Unit (SKU)

SKUs are unique codes defined by the seller. Unlike GTINs, which are often regulated by external agencies, SKUs are typically created by individual retailers or manufacturers for internal inventory management.

For example, a code like “TSHIRT-BLACK-XL” might be used to label and track different T-shirt variants.

3. Manufacturer Part Number (MPN)

The manufacturer part number (MPN) is simply the number a manufacturer assigns to differentiate one item from another in its product lines. It is often used for repair parts or technical components where it is important to get exactly the right piece.

4. Other Identifiers

Some platforms require their own standards. For example, Amazon uses the Amazon Standard Identification Number (ASIN), which is unique within the Amazon system. Other codes like Unique IDs (UIDs) or Product IDs (PIDs) also exist.

Although there is no universal standard for every situation, they all share the basic goal of organizing product information efficiently.

A Quick Look in a Table

Here is a table summarizing the top identifiers, who assigns them, their main uses, and an example for each:

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Practical Roles and Real-World Functions

1. Inventory Management and Tracking

Proper product identifiers form the basis of inventory management. They help maintain an accurate count of what’s in stock and what needs restocking.

Whether you’re selling socks or high-tech gadgets, tying each item to a unique code allows software systems to monitor activity in real time.

• Preventing Stock Errors. When an invoice shows 50 units, scanning the barcodes linked to GTIN codes lets you quickly reconcile with what is recorded in the warehouse.
• Predicting Demand. With steady data, historical sales figures become clearer, enabling data-based decisions about future stock needs.

2. E-commerce and Retail Operations

Identifiers connect physical stores and online channels. I worked with a client who was moving from a physical store to an online presence. The data migration was smoother because every product had a standardized identifier.

• Easy Scanning: Whether at a retail register or a distribution center, scanning a barcode linked to a GTIN or SKU is fast and reduces human error.
• Product Listings: Marketplaces like Amazon, Walmart, or eBay usually require a recognized identifier (GTIN, EAN, or UPC) when listing an item, ensuring that products match search queries correctly.

3. Supply Chain Efficiency

In an earlier project with a small manufacturer serving several regions, the lack of matching product codes between the manufacturer and retailers caused problems. Implementing standardized identifiers like GTIN helped improve communication between all parties.

1. A Common Standard: When manufacturers, distributors, and retailers all use GTIN or MPN codes, confusion is minimized.
2. Smoother Logistics: Standardized codes mean that products can move quicker through the supply chain because every party recognizes the identification.

4. Regulatory Compliance and Safety

In industries such as pharmaceuticals, medical devices, and chemicals, product identifiers are required. They allow regulators to track a product from production to the consumer.

For example, if a medication is later found to have an issue, the batch can be quickly recalled using the product’s unique code. Without that code, sorting through millions of items would be extremely difficult.

5. Product Differentiation and Authentication

Counterfeit goods are common. I once read about fake consumables that looked nearly identical to the real products. Without official product identifiers, verifying the authenticity of an item becomes much harder.

Some companies include special codes or extra barcodes like QR or data matrix codes, allowing customers to verify a product’s authenticity by simply using their phone to scan the item.

6. Data Collection and Analysis

If you pay close attention to data when making business decisions, you’ll appreciate that product identifiers feed valuable information into your analytics. Over time, the combined data from each SKU or GTIN can reveal:

• Which size or color variant sells best
• Patterns in customer buying behavior
• How products perform across regions, sales channels, or different seasons

The Evolution of Product Identifiers

There is a common misconception that product identifiers belong only on old warehouse shelves. In truth, they have advanced considerably in modern times.

• Online Marketplaces: When listing a product on Google Shopping, the system uses the product’s GTIN to better match search queries, helping your product appear for the appropriate keywords.
• Omnichannel Commerce: Today’s consumers might first notice your product on social media, then buy online and finally pick it up in-store. A consistent identifier helps link these steps together.
• NFC and RFID: Technologies such as near-field communication (NFC) and radio-frequency identification (RFID) are increasingly connected to product identifiers. Instead of scanning a barcode, a wireless reader can detect each item automatically.

Tips for Implementing Product Identifiers Effectively

Here are some suggestions based on my own experience:

• Start Early: Assign identifiers as soon as you create or source a new product. Waiting too long can create confusion as you grow.
• Pick a Consistent Format: If you generate SKUs internally, establish a clear naming system. For example, “TSH-RED-L” might represent a red t-shirt in a large size.
• Integrate Systems: Make sure your e-commerce platform, warehouse management system, and any other software use the same identifier.
• Educate Your Team: It is important that everyone—from warehouse staff to the marketing team—knows how to read and create these codes.
• Stay Compliant: For products intended for the international market, it is wise to obtain official barcodes or GTINs from organizations like GS1.

Potential Pitfalls to Watch Out For

Implementing product identifiers can be tricky if not done carefully. Here are a few common issues:

1. DuplicatesDifferent departments might accidentally create separate SKUs for the same product. This leads to confusion when some team members refer to one code while others use a different one.
2. Unclear or Overcomplicated CodesSome companies design codes that are so long and random that they are hard to remember. Keeping them short, meaningful, and easy for technology to scan is key.
3. Failure to UpdateWhen a product changes in size or design, a new code might be needed. Using an old code for a new variant can cause problems with listings, returns, or compliance.

Can You Get Away Without Product Identifiers?

In a small local market or a one-person shop, you might think product identifiers are optional. If you have only five handmade products, you might remember them all.

But when you start growing or listing on larger platforms, a systematic approach becomes necessary.

Here is a quick checklist of situations where using product identifiers is a must:

• Listing on major marketplaces like Amazon, Google Shopping, or Walmart.
• Tracking thousands of items in a warehouse.
• Selling in multiple countries where different barcode standards, such as UPC or EAN, apply.
• Meeting regulatory requirements, especially in sectors like healthcare or pharmaceuticals.

The Future: More than Just Barcodes?

We might think of product identifiers simply as numbers on barcodes, but new technologies are making their mark:

1. Blockchain is being used for supply chain transparency. Each product can have a digital record that confirms its authenticity and tracks its progress from production to the buyer.
2. Smart packaging can interact with mobile devices or scanners to share product details, important disclaimers, or usage instructions.
3. IoT (Internet of Things) integration in some product categories means, for example, that a refrigerator might scan product codes or RFID tags and automatically create a shopping list.

These advances all depend on the idea of a unique identifier, proving that product identifiers remain a central part of how products are managed and tracked.