SKU, EAN, UPC, GTIN, ISBN, ISSN – What these codes are and how to add them in WooCommerce

If you have an online store you should know the SKU, EAN, GTIN, UPC and ISBN codes, know what they are, what they are for and how to use them in your Ecommerce, so let’s see them in detail.

SKU, EAN, UPC, GTIN, ISBN, ISSN, what are they, what is each one for?

As I know that there are many misunderstandings, I will try to explain briefly what each of these codes is, what they are used for and above all how they differ.

I’m sure you will understand quickly how to use them in your WooCommerce online store.

SKU

The SKU or Stock Keeping Unit is a code normally composed of letters and numbers that serves to synchronize warehouse and store inventory in the same business.

The SKU can have any length you want but it is recommended that it is not very long, at most 12 or 14 characters in total.

Usually, SKUs are generated by the company’s ERP software, and when they are well defined they are a fantastic tool to quickly identify references within the company.

For example, if you sell computers and you have a Toshiba-branded, 2021 model AS100, the SKU generated might be something like TOS-AS100-2021.

How to enter and display the SKU in WooCommerce

Here we have it easy, because WooCommerce already incorporates a field in which to enter the SKU in both simple and variable products.

In the product data, in the inventory tab if it is a simple product.

Or in the data for each variation in the variable products.

In the store, although it depends on the theme, it will usually be seen below the add to cart button.

If, for some reason, you do not want to use and/or display the SKU in your online store, you can do it with the following guide…

EAN

The EAN code, or European Article Number, is composed of 13 numbers (without letters) and 18 bars of different thickness, and is the usual bar code that we are used to seeing on products in stores.

It is a unique code for each specific product of a manufacturer, no matter who sells it and where, it is an international code, valid in the European Union.

How to enter and display the EAN in WooCommerce

There are several ways to enter and display EAN codes in your online store created with WordPress and WooCommerce.

Use SKU field

A very simple solution, if your company or online store does not use the SKU code is to use this field, already included in WooCommerce, to enter and display in it the EAN of each product or variation.

You would enter it as we saw before, except that everything will be numbers, but as the field is free text there is no limitation.

The only thing missing is to change the visible text in the store, something simple if you review the following tutorial:

And you would already have your EAN field using WooCommerce’s internal SKU functionality. Both in the data entry interface…

As in the visible part of the product…

With plugins

If you also need the SKU field, or just want to control more how to display the EAN field, the best is to use plugins.

And the best by far is Product GTIN (EAN, UPC, ISBN) for WooCommerce, totally free.(Now a closed plugin and no longer available)

Once installed it is almost ready to use, and the best thing is that you can use it not only for the EAN, but you can customize it and use it for the rest of the codes (UPC, ISBN, GTIN).

The first thing is to configure how and where you want the EAN to be displayed, in the plugin settings, which will be in the administration of your site, in WooCommerce -> Settings -> EAN of products.

In the above screenshot I write down what each setting is for and which ones are recommended.

In the case of structured data, choose the code gtin13 for the EAN, because it refers to the 13-digit code, which is the EAN code.

Below, you will find the field for entering EAN codes in the editor, in the product data.

In the inventory tab in the case of simple products…

And in every variation in the variable products…

And, of course, it will be perfectly visible on the product page and everywhere you have configured.

As I said, it is the best method to add the EAN code in WooCommerce.

Now, if you want to display the barcode associated with the EAN automatically there is another plugin, this one paid, called EAN for WooCommerce, whose main difference is this, that creates the barcode, and you can make it visible in your online store.

I think it does not add anything essential in an online store, but look, this is a matter of taste, and it is not expensive, it costs only $19 per site.

ISBN and ISSN

The ISBN, or International Standard Book Number, is a type of EAN, an international standard number for identifying books by a 13-digit numerical code.

The ISSN, or International Standard Serial Number, is used for periodic publications or serials, such as magazines or serials, and also follows the 13-digit EAN standard.

It is not mandatory but guarantees that it will appear in all international book catalogs. The ISBN cannot be assigned on your own, it must be requested, and costs about 45€.

How to enter and display the ISBN or ISSN in WooCommerce

There are several ways to enter and display ISBN codes in your online store created with WordPress and WooCommerce.

Use SKU field

Just as with the SKU, if you have an online store where you sell only books and you don’t use the SKU field, use this field.

Then, just as we saw in the EAN section, rename the SKU and you have it.

With plugins

Again, my recommendation is the free plugin Product GTIN (EAN, UPC, ISBN) for WooCommerce, and not only because you can change the tag globally to display the ISBN or ISSN instead of EAN, but because you can do it on each product. Let me explain…

If you have an online store where you only sell books, it is enough to configure the plugin so that the visible label is ISBN or ISSN.

But in case you have a mixed online store, in which you sell everything, and in some cases you use EAN and in others ISBN or ISSN, then we do something else.

If this is the case, configure the plugin with the most common code label (EAN, ISBN or ISSN) and then, in the product, you will see a field in which, for that product, you can configure a different label.

Which will be the one that will be seen in that product (book).

UPC

The UPC number, or Universal Product Code, mainly used in the USA, is a 12-digit numerical code and its corresponding bar code.

How to enter and display the UPC in WooCommerce

As with the previous ones, there are ways to enter and display UPC codes in your online store created with WordPress and WooCommerce.

Use SKU field

Just as with the SKU, if you have an online store where you sell only books and you don’t use the SKU field, use this field.

Then, as we saw in the EAN section, rename the SKU, put UPC and you have it.

With plugins

And, again, we will use the wonderful plugin Product GTIN (EAN, UPC, ISBN) for WooCommerce.

Here, remember to change the label in the global settings, so that it shows UPC.

Which is what will later be seen in your online store.

GTIN

The GTIN number, or Global Trade International Number, is a 12 to 14 digit code, which is replaced by the EAN (in the EU) or the UPC (in the USA).

To summarize, the international barcode standard is the GTIN, but in the European Union it is replaced by the EAN, in the USA by the UPC and in books by the ISBN everywhere.

How to enter and display the GTIN in WooCommerce

As with the previous ones, there are ways to enter and display GTIN codes in your online store created with WordPress and WooCommerce.

Use SKU field

Just as with the SKU, if you have an online store where you sell only books and you don’t use the SKU field, use this field.

Then, as we saw in the EAN section, rename the SKU to GTIN and you have it.

With plugins

And, of course, again, we will use the free gem called Product GTIN (EAN, UPC, ISBN) for WooCommerce.

Just change the tag in the settings and you’re done.

You will have the GTIN field in your product sheet, which will be visible in your online store if you want it to be.

What did the codes mean?

If, at this point, you have a bit of a mess, I will summarize each code for you:

• GTIN – International GTIN code (14 numeric digits)
• UPC – GTIN code used in the USA (12 numeric digits)
• EAN – GTIN code used in the European Union (13 numeric digits)
• ISBN – GTIN code used internationally for books (13 numeric digits)
• SKU – Internal warehouse code, different for each business (recommended between 8 and 12 alphanumeric digits).

Read this post in Spanish: SKU, EAN, UPC, GTIN, ISBN, ISSN – Qué son estos códigos y cómo añadirlos en WooCommerce