How to Fix “External Product ID Is Shorter Than the Minimum Allowed (13 Characters)”

When sending a product to Amazon, you may receive the following error message:

The value of “External Product ID” is shorter than the minimum allowed (13 characters).

What Does This Error Mean?

Amazon requires a valid 13-digit EAN barcode for the affected product or combination. This error occurs when:

• The barcode entered in PrestaShop contains fewer than 13 digits.
• A 12-digit UPC code was entered into the EAN-13 field without a leading zero.

Correcting One Product Manually

1. In PrestaShop, navigate to Catalog > Products.
2. Open the affected product.
3. Check the EAN-13 field.
4. If the error concerns a combination, go to the Combinations tab and check the EAN-13 of that specific combination.
5. Correct the barcode, click Save, and re-verify the product in the Amazon module.

Handling a 12-Digit UPC Barcode

If the barcode contains exactly 12 digits, confirm that it is a valid UPC code. You can convert a valid 12-digit UPC into an EAN-13 format by prepending a 0 at the beginning.

• UPC: 123456789012
• EAN-13 representation: 0123456789012

Warning: Do not add a leading zero to an incomplete, truncated, or invalid barcode.

Correcting Multiple Products Using SQL (Bulk Update)

If you have many products with 12-digit UPC codes stored in the EAN-13 field, you can update them in bulk using SQL queries in phpMyAdmin or your server database manager.

Important Recommendations Before Proceeding:

• Always create a full database backup before executing any UPDATE queries.
• Always run the SELECT queries first to verify which rows will be modified.
• Replace ps_ with your actual database prefix if your store uses a custom prefix (e.g., prestashop_).

Step 1: Preview Affected Products (SELECT Queries)

Run these queries first to verify which products and combinations contain 12-digit barcodes:

Standard Products (Without Combinations):

SELECT id_product, reference, ean13
FROM ps_product
WHERE CHAR_LENGTH(ean13) = 12
AND ean13 REGEXP '^[0-9]{12};

Product Combinations:

SELECT id_product_attribute, id_product, reference, ean13
FROM ps_product_attribute
WHERE CHAR_LENGTH(ean13) = 12
AND ean13 REGEXP '^[0-9]{12}$';

Step 2: Prepend Leading Zero (UPDATE Queries)

After confirming that all returned entries are valid 12-digit UPCs, execute the following queries to add the leading 0 and convert them to 13-digit EANs:

Standard Products (Without Combinations):

UPDATE ps_product
SET ean13 = CONCAT('0', ean13)
WHERE CHAR_LENGTH(ean13) = 12
AND ean13 REGEXP '^[0-9]{12}$';

Product Combinations:

UPDATE ps_product_attribute
SET ean13 = CONCAT('0', ean13)
WHERE CHAR_LENGTH(ean13) = 12
AND ean13 REGEXP '^[0-9]{12}$';

Final Step

Once the SQL updates are complete, clear your PrestaShop cache, and resend the affected products to Amazon.

Updated on: 07/08/2026