Facility standards and audits
Ask which food-safety scheme the site operates to, when it was last audited and by whom, and how allergens and sanitation changeovers are controlled between products.
Formats, minimums and scale-up
Line format usually decides the supplier. Confirm fill sizes, container types and the minimum run, then ask what a scale-up path looks like if the product sells.
Labeling and claims
Agree in writing who is responsible for label content, nutrition panels and any claims. The brand owner usually carries that responsibility even when the co-packer prints the label.