I'm currently running a staging copy of a live Magento 1.9 site. On this staging site I have noticed that if I attempt to add a new product with an SKU that begins with a letter (character between A-Z) (e.g. HOS2019), I get an error of

Please enter a valid number in this field.

If I begin the SKU with a number, the product is accepted and saved with no issue.

The live copy of this site accepts a product a letter at the beginning of the SKU with no issue, so I know something is not quite right with this staging copy of the site.

I was just wondering if anyone had ever come across a problem such as this, and what code I could possibly look at to try and resolve this - or indeed what code I could compare with the live version of this site to try and find the fault.

Many thanks for any light anyone can shed on this.

  • Maybe you've got an input validation set on the SKU attribute at Catalog -> Attributes -> Manage Attributes? Jul 2, 2019 at 22:19
  • 1
    I'm not sure if it is accepted to leave thanks here, but thank you Christoph for pointing me in this obvious direction - this solved my issue and I feel like a twonk! And also thanks to Raj for editing my scruffy text. Thank you all.
    – Vortex
    Jul 3, 2019 at 16:14

1 Answer 1


Product attributes (Catalog -> Attributes -> Manage Attributes) can have validation options set.

In your case "Input Validation for Store Owner" says "Integer". Change it to "None" or "Letters (a-z, A-Z) or Numbers (0-9)" in order to be able to set SKUs the way you want.

Edit Product Attribute "SKU" screen

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.