Custom fields - there are no options to say "must be unique"?

Custom fields - there are no options to say "must be unique"?

Good evening

If I am getting the user to enter in a Product Code - is there a way to check it is unique? Can't see any option and there is no WorkFlow action that I can see of that would check for this.

I can use auto number but our Product Codes come from our Vendor

Thanks for any comments.

Brynley