The following GS1 video explains the structure and components of a UPC (GTIN-12).

UPC Company Prefix

A UPC Company Prefix is a 6 – 10 digit number assigned to members by the GS1 organization in the United States.  The number of digits in a Company Prefix can vary between 6 – 10 characters, depending on the number of products a manufacturer needs to identify. A small company, who only needs to identify a single product, would receive a 10-digit number. The membership fee for GS1 is primarily based on the number of products which require identification.  As of October 2013, GS1 US dramatically reduced their pricing for small companies and the starting fee is $250 for 10 numbers.

Here’s an example of a GS1 Certificate which includes a UPC Company Prefix; UPC.Certificate

Item Reference Number

The UPC Company Prefix and Item Reference Number must always total 11-digits.   The amount of digits of an Item Reference number is dependent on  the length of the UPC Company Prefix assigned. The GS1 takes into account the amount of prospective products your company plans on selling when assigning a UPC Company.  For companies which sell many different items and need to assign more UPC (GTIN-12) numbers will receive a shorter prefix, allowing them to assign a larger range of digits for their products, while companies needing less UPC (GTIN-12) numbers will be assigned a longer UPC Company Prefix which will reduce the number of UPC (GTIN-12) numbers that can be assigned.

For organizations with a 6-digit Company Prefix, a 5-digit product number must be created. Companies with a 9-digit Company Prefix, can only create a 2-digit number. A unique Item Reference number is needed for each variety of item being sold.  For example, let’s say you’re selling t-shirts in two different styles – yellow and blue. The blue small, medium, and large t-shirts would each have their own unique product numbers, while the yellow small, medium, and large t-shirts would also have their own different unique product numbers.


Product Style Item Reference Number Full UPC (GTIN-12) Number
Blue Shirt – Small 1 01234500001-0
Blue Shirt – Medium 2 01234500002-7
Blue Shirt – Large 3 01234500003-4
Orange Shirt – Small 4 01234500004-1
Orange Shirt – Medium 5 01234500005-8
Orange Shirt – Large 6 01234500006-5

Check Digit

The 12th digit is a calculated digit based on a MOD check digit calculation from the 11 preceding digits. The check digit prevents substitution error, which would result if one digit read as another. It would be better for a barcode not scan at all than scan as an incorrect product.

To calculate check digit CALCULATE

To manually calculate the check digit using modulo algorithm, follow these 5 steps;
Example: If the first 11 digits of UPC code is; 01234567890

Step 1:

Add all of the ODD positions (1,3,5,7,9,11)

Step 2:

Multiply value from Step 1 by 3

Step 3:

Add all of the EVEN positions (2,4,6,8,10)

Step 4:

Add value from STEP 2 and STEP 3 together

Step 5:

Determine what number is needed to make value from STEP 4 into a multiple of 10.

Example 1:

Odd positions equals; 20 (0+2+4+6+8+0)

Example 2:

Multiply 20 x 3 = 60

Example 3:

Even positions equals: 25  (1+3+5+7+9)

Example 4:

STEP 2 and STEP 3 equals: 85 (60+25)

Example 5:

Check Digit is 5 (85+ 5 = 90)

Obtain a UPC Code

UPC numbers are not random numbers chosen by a brand owner. To ensure authenticity and to prevent duplicate UPC numbers from being assigned by different companies,  UPC number must contain a UPC Company Prefix issued by GS1, an Item Reference Number assigned by the brand owner and a check digit which is mathematically calculated.  

Two ways to obtain a UPC Number

  • Become a member of the GS1 and have a UPC Company Prefix issued to your company and assign your own UPC numbers.
  • Purchase a UPC Number from a UPC reseller.

Company Prefix issued to your company by the GS1

GS1 Company Prefix Blank

Companies who are suppliers (or hope to become suppliers) to national retailers, large grocery chains, or distributors, must become a member of the Global Standards Organization (GS1) and obtain a GS1 Company Prefix.   The reason many retailers, grocery chains, and distributors require their suppliers to become members of the GS1 and obtain their own UPC Company Prefix, is to ensure UPC (GTIN-12) numbers are unique and are registered to the company they’re doing business with.  UPC ownership can easily be verified by entering a UPC number on our online tool: UPC Ownership

The initial GS1 membership and annual renewal fee is dependent upon the number of UPC (GTIN) numbers which need to be assigned.

GS1 membership fee structure:

Number of Items Needing a Barcode/GTIN* Initial Fee Annual Renewal Fee
1 – 10 $250 $50
1 – 100 $750 $150
1 – 1,000 $2,500 $500
1 – 10,000 $6,500 $1,300
1 – 100,000 $10,500 $2,100

After receiving a GS1 issued UPC Company Prefix an Item Reference Number needs to be assigned and check digit calculated.

Company Prefix issued to a UPC Reseller

UPC Resellers are opportunistic companies which obtained UPC Company Prefixes prior to 2002 from the original numbering organization in the United States the Uniform Code Council (UCC). In the 1990s, the UCC and European Article Numbering Organizations (EAN) developed a cooperative arrangement which eventually laid the foundation to become the Global Standards Organization (GS1) in 2005.  During the conversion into becoming the GS1 US, the UCC updated their business practices to include an annual renewal fee which resulted in a class action lawsuit being filed against them.  In August of 2002, the UCC settled the lawsuit by paying damages of $3.89 million and amended the agreement for new companies who needed a UPC Company Prefix to state, “The license agreement for our membership prohibits any use of the Company Prefix other than for the use of the owner company, including but not limited to selling, sharing, leasing, sub-dividing, or re-selling the Company Prefix.” Since this statement was not included in the original application for companies who obtained UPC Company Prefixes prior to August 2002, UPC resellers use the settlement agreement as justification that they can sub-divide numbers from older prefixes. UCCClassActionNotice

As UPC bar codes have become a common requirement to do business with a retailer, grocery chain or distributor many more UPC resellers have emerged.  Since barcodes are a trading partner requirement, not a legal requirement, many UPC resellers are not reputable an intentionally attempt to confuse companies who are not to barcoding .  Many UPC Resellers use misleading claims such as, “Our UPCs originate with the GS1”, “Official UPC codes”, or “Authentic and Unique UPC barcodes”, as well as questionable business practices.  Prior to purchasing  UPC numbers from a UPC reseller, we strongly encourage clients to become aware of the limitations and potential liability with using a UPC numbers that aren’t registered to your company through the GS1.

Is purchasing a single UPC from a reseller legal?

Including UPC barcodes on products is not a legal requirement, it is a trading partner requirement, which means the company who is asking for a UPC symbol to be included on their items is responsible for ensuring UPC compliance.  Many larger retailers, grocery chains, and distributors explicitly state in their Supplier Requirements that suppliers must obtain a UPC Company Prefix from the GS1.  For example, Wal-Mart, Macy’s, Kroger, Sears, SuperValue and many other companies require suppliers to provide a copy of their GS1 Certificate, which includes their UPC.CompanyPrefix, during their vendor onboarding process.  Other retailers, grocery chains, and distributors use an online tool to verify UPC Ownership.  We suggest asking your trading partner if it is okay to mark your items with UPC symbols obtained from a UPC reseller.

Does Amazon allow suppliers to use barcodes obtained from a UPC Reseller?

To be honest, we’re not sure if Amazon permits or prohibits the use of barcodes from a UPC reseller.  Amazon recently updated information available on Seller Central and explicitly states that Amazon requires sellers to obtain ‘valid’ UPC’s from the GS1 and that Amazon will confirm UPC barcodes are registered to their sellers and not 3rd parties.  However, in the past Amazon recommended sellers obtain UPC codes from any source including UPC resellers.  It’s possible, that Amazon is encountering issues from UPC barcodes being purchased from resellers which is polluting Amazon’s Product Registry and is now requiring sellers to work with the GS1.

We have worked with several Amazon suppliers who reported that during the vendor set-up procedure, Amazon flagged their UPC numbers for either of the following reasons;

  • UPC Numbers were already being used by a different supplier
  • UPC numbers were not issued to supplier being set-up.

In both cases, Amazon required the supplier to obtain a UPC Company Prefix from the GS1.

What are the potential issues with obtaining a UPC from a reseller?

  • The most significant issue with using a UPC from a reseller would be if your products were rejected by one of your retail clients and the items needed to be relabeled.
  • If your company expands into different retailers and one of your new trading partner required GS1 membership.  All of your product information would need to be updated with all of your trading partners and all products would need to be re-labeled.
  • The UPC number issued to you by the reseller is being used by another company as a result of one of their other clients poaching the UPC Company Prefix and assigning their own Item Reference Numbers.  This could happen if a company isn’t aware that they initially purchased a UPC number a reseller and then followed the GS1 General Specifications.  In other words, it is possible that a company could assign a UPC number using a UPC Prefix that does not belong to them and have the same UPC trying to be used at the same retail store.
  • Using a UPC number that does not include your own UPC Company Prefix will prevent your company from being able to use other barcodes which use a GS1 Company Prefix.  For example, many retailers, grocery chains and distributors require additional barcodes such as GTIN-14 and SSCC-18. In order to generate these other barcodes, your company must have their own GS1 Company Prefix.
  • Since UPC resellers are generally internet storefronts, there’s no way of really knowing who you are doing business with and providing your credit card information to.  We’ve had a few reported cases of offshore companies posing as UPC resellers, with the sole purpose of taking credit card information.

Is it ever a good idea to use a UPC from a reseller?

 Yes. If your company needs more than 100 UPC (GTIN-12) numbers and is doing business with boutiques, smaller retail stores, or online stores and you don’t envision selling to larger retail outlets, it’s possible that a UPC from reseller may be a good fit.  As noted, we strongly recommend discussing with your trading partner whether or not they permit the use of UPC numbers obtained from resellers.

 UPC Size

Size Requirements

In order for a UPC symbol to be scannable, it must be generated within the acceptable size range.

Color Guidelines

In order for a barcode symbol to be recognized by a scanner, there must be an adequate contrast between the dark bars and the light spaces. Since most barcode scanners operate with a laser which identifies “red” as white, it is extremely important that appropriate bar and space colors are determined.

Color Chart

The chart below provides a simple illustration of adequate color combinations.

check markScannable Color Combinations


UPC Scannable Color Combinations

stop mark Non-Scannable Color Combinations


Revised UPC Non-Scannable Color Combinations

Mark Product with UPC Symbol

There are 2 ways to mark items with a UPC Symbol

Incorporate UPC directly onto package or packaging label




Affix a pressure sensitive label (sticker) onto the item

person applying label

The best options depends on several factors

  • Does your item have custom packaging?  If it does, then incorporating the label into the package design would be

In choosing whether or not printing labels in-house using an on-demand printer (laser or thermal), or having a 3rd party printer provide printed UPC labels, we suggest contacting Bar Code Graphics to assist.  We support companies by providing; barcode label software, blank labels as well as printed barcode labels.






  • UPC (GTIN-12)

  • ISBN/Books

  • Medical/UDI

  • Supply Chain

  • Assets/Inventory

  • Coupon

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There are a variety of different types of barcodes. However, the UPC (Universal Product Number) symbol is the most recognized barcode in the United States, since it appears on almost every retail product. The UPC symbol is the barcode representation of the GTIN-12 which consists of twelve numeric characters that uniquely identify a company’s individual product. The GTIN-12 number is part of the family of GS1 global data structures that employ 14 digits and can be encoded into various types of data carriers.

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A requirement for selling a book through booksellers, wholesalers, and distributors is the assignment of unique ISBN numbers for each title and for each book to be marked with a Bookland EAN barcode.

The Bookland symbol allows for encodation of ISBNs (the numbers publishers use to identify their products). Since an ISBN is unique to one particular title (or product), the corresponding Bookland EAN symbol is a title-specific marking which is unique for that title. For example, if a title is available in hard cover, soft cover and as an e-book, three unique ISBN Bookland EAN bar codes are required.

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The FDA UDI Mandate is part of a comprehensive healthcare traceability initiative to improve patient safety.  The Unique Device Identifier (UDI) requirement is rooted in holding each member of the supply chain responsible for ensuring each medical device is marked with a UDI barcode with data maintained on the FDA’s GUDID universal database.

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Supply Chain

Logistic barcodes such as the GS1-128 Shipping Label are used to track movement of a shipment within a supply chain.  Since suppliers are making shipments to a variety of trading partners it is essential to integrate the relevant standards and current technology.  The use of EDI and 2D barcodes which can encode much more data has transformed many supply chains.

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The first step in designing an asset tracking system is to determine whether you are working with assets or inventory.  Assets are any items a company uses internally such as tools, equipment, furniture etc.  Inventory are items which are sold, distributed or used by a company.  The distinction between Assets and Inventory is essential in regards to how the items will be marked, scanned and stored.

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The successful integration of GS1 DataBar Coupons has dramatically improved many promotions.  The interhent features including; value codes and automatic expiration date checking for retailers, has enabled more efficient redemption, much better security and better metrics to measure the performance of a campaign.

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Barcode Graphics

Barcode Graphics