Those Darn Zeros - 14 Digit GTIN's

by Paula Giovannetti

Many North American companies are confused by the various rules for creating Global Trade Item Numbers (GTIN).  In an attempt to make sense out of the various data structures and bar code symbologies used to identify items around the world, GS1 (new name for the combined UCC and EAN International) has created the term “Global Trade Item Number”.  The text book definition of a GTIN is as follows:

    “Any item (product or service) upon which there is a need to retrieve
     pre-defined information and that may be priced, or ordered, or invoiced
     at any point in the supply chain.”

Trade items basically come in two varieties, those that are scanned at a Point of Sale (POS) device and those that aren’t.  GTIN’s that are not intended to be scanned or sold at POS include inner packs and cartons.  A pallet full of product can also be considered a GTIN if it is bought and sold in that configuration, as is often the case in grocery.

Global Data Synchronization

The plot thickens with Global Data Synchronization (GDS), which is just a fancy way of saying we need to exchange current and accurate data about what we are selling to each other.  That data includes things like the GTIN, description, weight, size, color, price, unit of measure and so on.  Over the years we have created multiple data bases with item information and often those data bases are not synchronized within our own enterprise, let alone between trading partners.  The answer, of course, is good old fashioned process engineering and discipline.  Simple, but not easy.  There should be one single location for item information, and all other systems should pull from that location.  Descriptions should be meaningful – something besides “apparel” or “shoes”.  As we role out Dynamic Routing, weight and cube must be correct, not just a guess or approximation. 

Audit trails will track who, what, when and where as changes to the data are made.  Changes to data should always be transaction-based.  That is, no one is allowed to directly access a data base to make changes.  They create a change record which indicates who make the changes, when and why.   When that change record is processed, all appropriate data bases are updated.  This assures internal data synchronization.

Part of Global Data Synchronization is to assign GTINs to packaging levels that do not strictly fit the above official definition of a trade item.  GS1 is suggesting that we assign GTIN’s to all possible configurations of our product, whether or not we sell them that way.  One of the challenges we face in the purchase order-shipping-receiving cycle is we want to talk in “eaches” on the PO and invoice, but we want to ship the product in the most efficient way, protecting it from damage in transit.  In order to do this we want to order and ship in carton or pallet loads.  If ten cartons fit nicely on a pallet, then we don’t want to get an order for eleven or twelve.  Inner packs are handy when we ship product to a customer when they order less than a case pack, or when a customer wants to distribute inner packs to individual stores.  So we have lots of package configurations that may never be ordered that way and will certainly never see a POS device – but help us handle product more effectively.  That means we have to give them a “name” so they get their own GTIN.

Using the UCC-12 to Mark Inner Packs and Cartons

Why do we have EAN.UCC-14 (fourteen digit) GTIN’s?  We can just assign a UCC-12 number and put it in a U.P.C. bar code symbol on every item and then put a different UCC-12 and U.P.C. code on the inner pack and another one for the carton and yet another for the pallet.  Well, actually, technically, you can do that, and many companies do.  We can use something called a “large U.P.C.” on cartons.  That’s a U.P.C. that is up to twice as big as a regular U.P.C.  If a U.P.C. is made any larger than that, then it does not scan well.  Reading a bar code depends greatly on the specific size of the bars and spaces.   But it turns out that reading “large U.P.C.” in a high speed sortation environment is not the most efficient way to go.

We can assign unique UCC-12’s to the inner pack, case and pallet and use a different kind of bar code symbology.  There are two types of bar codes we can use – Interleaved 2 of 5 (ITF) and UCC/EAN –128.   We generally use ITF on corrugated cardboard boxes.  That’s the bar code with the heavy “bearer” bars on the top and bottom of the symbol.  Because it is difficult to read bar codes when the edges are fuzzy (like when ink jet is sprayed on the carton and the edges feather), there are certain rules for ITF symbols.  The data they carry can only be numeric and it must be an even number of numbers.  Because, in the EAN.UCC system, the rest of the world uses an EAN-13 (like we use our UCC-12), they created ITF-14 symbology.  To get to an even number of numbers that could accommodate both UCC-12 and EAN-13, we use fourteen digits. Therefore, when sending a UCC-12 number in an ITF bar code, you must pad with two zeros.  These zeros are added right before the data is converted to a bar code, and stripped when the bar code is read, so that the output is the UCC-12 number without the zeros.

The same rules apply when creating a UCC/EAN-128 bar code symbol.  If you are using a UCC-12 to identify the carton, you put two zeros in front to create the symbol, and strip them away after reading the symbol.

It is very important to note that you cannot use a UCC-12 number in a U.P.C. code on the individual item, and then put two zeros in front of that same UCC-12 number to “uniquely” identify the carton level.  A UCC-12 with or without the two zeros is the same number.  In this case you have not assigned a different number at the each and carton level.  Bar code readers will see it as the same number at both levels.

Indicator Digits  

But as long as we have two numbers to play with – why not make them useful?  We can do this by creating an EAN.UCC-14 GTIN with an Indicator Digit using one through eight.  Assigning EAN.UCC –14’s is one way to organize package configurations when inner packs, cartons and pallets contain the same UCC-12.  The fourteen digit number is built by using the UCC-12 number from the “each”, and adding the number one through eight, followed by a zero (and recalculating the check digit) to make it fourteen digits.  We now have a unique number and a way to identify different package configurations of the same item.  We can look it up in our data base to see if it is an inner pack, carton or pallet, plus store the attributes for that package – weight, cube, quantity, and so on.

When the first number is a nine it means it is variable measure (you need the weight or length to identify the item).  As we learned above, when the first two numbers in a fourteen digit GTIN are zero, that means it is really a UCC-12. 

So the Indicator Digit is a useful way to use the first digit in an EAN.UCC-14.  What is the next digit used for?  The next digit, in North America, is a zero because it is used as our “country code” and is part of the overall scheme in keeping EAN.UCC Keys, like the GTIN, truly unique in the world.  When we put a zero in front of our UCC Company Prefix we have an EAN.UCC Company Prefix.  We currently encode all thirteen digits (the UCC-12 plus the zero) in a U.P.C. bar code.  Over the years we have simply “suppressed” the first zero and our systems only read twelve digits and exchange twelve digits in the PO, invoice, shipping notice, etc.  We do not use that extra lead zero in the human-readable number that goes below the U.P.C.  We do use that zero for every EAN.UCC Key except the UCC-12 in a U.P.C. bar code.  For instance we use that zero in front of our Company Prefix when we create a Serial Shipping Container Code (SSCC) or a Global Location Number (GLN).  Don't be confused by the fact that the human-readable below the U.P.C. bar code often starts with zero.  That is not the "country code" suppressed zero.  That is the first digit in the UCC Company Prefix.  Currently there is no movement to start reading, using, or exchanging that "thirteenth digit" (the extra lead zero in the U.P.C.).

Take a deep breath, and let's review.  A UCC-12 with two zeros in front of it is a UCC-12 in the "fourteen digit GTIN format".  A UCC-12 starting with indicator digit one through eight is an EAN/UCC-14.

GTIN Compliance

GTIN compliance is defined as knowing how to assign, mark in bar codes, and exchange all four types of GTIN’s.  The four types are EAN-8 and EAN-13, the UCC-12 and the EAN.UCC-14 (Indicator Digit one through eight).  While there is no official mandate to be GTIN compliant – it is the smart thing to do.  We will use fourteen digit GTINs for RFID and Global Data Synchronization.  Plus, carton content marking for inner packs and standard case packs will help us maintain a more efficient supply chain.

Those Darn Zeros

One of the biggest challenges in becoming GTIN compliant is learning to handle a UCC-12 with and without the two zeros used to create fourteen digit bar codes and convey trade item information for GDS.  This, of course, could involve major changes and major expense as you alter your systems.  Please keep in mind that these are just suggestions and it is important to think through any solution thoroughly.

What’s the Objective?

First, let’s define our objectives:

1).  We need the ability to scan and look up U.P.C. codes (which will NOT have fourteen digits).  The scanner will read a twelve digit number and you must be able to match this twelve digit number in the bar code to the UCC-12 in your system and your trading partner’s system.

2.)  The ability to handle requests from your trading partners to receive, process and send a UCC-12 converted to the fourteen digit “GTIN Format” – that is with the two zeros.

3.) Take advantage of fourteen digit carton marking using the ITF-14 and EAN.UCC-128 bar code symbols.

4.)  Be prepared for RFID and Global Data Synchronization

Keep Your Data at Twelve Digits

You can keep your systems just the way they are, with UCC-12 and U.P.C.  If your trading partner wants to pad the data with two zeros for exchanging EDI then use the “UK” qualifier and just add and strip zeros at the EDI translator level.  This is how most companies seem to be handling it at this time.  This is similar to the way you create fourteen digit bar codes from a UCC –12; you add the zeros right before encoding the bar code and take them out when decoding the data.  Similarly, with RFID, as you build the Electronic Product Code (EPC) you add zeros and remove them when the data is read.

If you are required to convey the zeros when populating Global Data Synchronization data, you can ask your Data Pool service provider to add and remove the extraneous zeros and simply communicate with them using your UCC-12 number.

Using Fourteen Digits

The other method you may use to handle those two zeros is to create a cross reference field in your data bases, one with the zeros and one without.  You would use the one without to create and read U.P.C. plus communicate with trading partners still using the “UP” qualifier in EDI, which denotes the twelve digit variety of GTIN.  Please remember that the U.P.C. bar code will continue to house twelve digits. The cross reference field with the two zeros is used to communicate with trading partners asking for fourteen digits, creating fourteen digit bar codes (ITF-14 and UCC.EAN – 128), EPC’s and for Global Data Synchronization.

The most important thing to remember is that UCC-12’s in U.P.C. symbology will only have twelve digits, and for North American suppliers, will be in use for a long time.  It’s worth repeating:  as we are set up to read and process U.P.C. in North America today, the data is twelve digits, the structure is twelve digits and the bar code will read twelve digits.

It is painfully obvious that we will have to pay close attention to the way we manage our GTIN’s as we get requests for our good old, trusty, UCC-12 from some trading partners and the fourteen digit variety from others. It will be a tricky transition.  It’s like that old story about the country converting from driving on the left side of the road to the right side.  Their plan called for converting cars on the first day and the trucks on the second.

Post Script:   GS1 (EAN/UCC) is in the process of changing terminology to fit their new GS1 name. 

GTINs are:  GTIN-8 (EAN-8), GTIN-12 (UCC-12), GTIN-13 (EAN-13), GTIN-14 (EAN/UCC-14, indicator digit 1-9). 

The UCC/EAN-128 bar code symbology is now the GS1-128 symbology.

 This is an updated, edited excerpt from an article written for the Compliance Advocate.