One of the key analysis carried out by Test My Feed is that for EAN, UPC and ISBN data, collectively called “GTIN” on a standard Google product submission, but classified separately on other shopping comparison websites.

For all of these, “EAN” is used below to explain what we are looking for within our testing.

The reason that EAN validation is so important is that many channels automatically associate an EAN (barcode) with existing inventory on upload.

This creates real problems in any of the scenarios below

1. Same EAN applied to 2 or more different products
2. Same EAN applied to multiple child variations within a single parent product
3. EAN applied to the wrong product
4. Invalid EAN applied to a product.  This can be because the EAN does not have the  correct number of digits, is entered into your database incorrectly (digits mixed up), or uses an EAN that’s inapplicable to the region (ie using EANs starting with 2 which are French but are invalid for the UK)

While Test My Feed will identify incorrectly formatted and duplicated EANs, if a number passes our standard verification checks, in theory it could be used.

All of the other misapplications of otherwise correct EANs are not easily diagnosed, but can generate nasty repercussions for merchants

So, we recommend that this aspect of data quality is well worth paying attention to and to make sure your EANs are correct:

1. Run an analysis within your system to verify any EAN data you have already used
2. Check the boxes of the products concerned
3. Get suppliers to supply you with the barcodes (but careful here as we have seen suppliers also get the data wrong)

However, this is time well spent, particularly if you want to target Marketplaces or any Comparison Shopping Engines that use this reference data for listing/ranking purposes.