Co-packing is the work of putting your product into the pack a customer buys, under your brand. Co-packaging and contract packaging name the same work. A co-packer is the plant you hire to do it. The market uses those nicknames loosely. The agreement should not.
What a co-packer does
In commercial use, a co-packer places your product into the bottle, pouch, carton, canister, or multipack you will sell, and may label, code-date, and case it. Some plants only pack. Others also blend, cook, bake, extrude, or encapsulate.
A co-manufacturer makes the product. It turns ingredients into a food, beverage, or supplement, and often packs it too. Ask whether this plant will make, pack only, or supply its own formula.
Private label means the manufacturer already owns the formula and you apply your brand to it. A tweak does not transfer ownership. If another brand must not be able to reorder that formula from the same plant, private label is the wrong deal, even when the plant also co-packs.
When the nicknames collide with the rule
FDA does not define "co-packer." 21 CFR Part 117 is titled "CURRENT GOOD MANUFACTURING PRACTICE, HAZARD ANALYSIS, AND RISK-BASED PREVENTIVE CONTROLS FOR HUMAN FOOD."
Section 117.3 defines packing as "placing food into a container other than packaging the food" and also includes re-packing and activities incidental to packing or re-packing. Packing does not include activities that transform a raw agricultural commodity into a processed food as defined in section 201(gg) of the Federal Food, Drug, and Cosmetic Act. Manufacturing/processing means "making food from one or more ingredients, or synthesizing, preparing, treating, modifying or manipulating food, including food crops or ingredients." Examples include bottling, labeling, and "packaging (including modified atmosphere packaging)." Bottling or packaging a processed food is often manufacturing/processing under Part 117, even when your team calls it co-packing.
Section 117.126 requires a written food safety plan, prepared or overseen by one or more preventive controls qualified individuals, where subpart C applies. The plan includes the written hazard analysis, preventive controls, supply-chain program, recall plan, and the written monitoring, corrective-action, and verification procedures named in that section. Section 117.5 exempts some activities from subparts C and G when its conditions are met, including "the manufacturing, processing, packaging, or holding of a dietary supplement that is in compliance with" 21 CFR Part 111 and section 761 of the Federal Food, Drug, and Cosmetic Act. Ask which rule covers your product, and ask to see the program. This note is not a product-specific determination.
Registration is a filing, not an approval
Under 21 CFR 1.225, the owner, operator, or agent in charge of a domestic or foreign facility engaged in manufacturing/processing, packing, or holding food for consumption in the United States must register, unless § 1.226 exempts the facility. Section 1.230 requires registration before the facility begins to manufacture, process, pack, or hold that food, and renewal every other year during the period beginning on October 1 and ending on December 31 of each even-numbered year.
Section 1.242 states that assignment of a registration number means the facility is registered with FDA and "does not in any way convey FDA's approval or endorsement of a facility or its products." Section 1.226(g) provides that this subpart does not apply to facilities regulated exclusively, throughout the entire facility, by the U.S. Department of Agriculture under the Federal Meat Inspection Act, the Poultry Products Inspection Act, or the Egg Products Inspection Act. Ask which agency covers the plant.
When a brand should use one
Use a co-packer or co-manufacturer when the SKU needs equipment, a food-safety system, or throughput you do not have, and owning the plant is not the business you are building. Settle who owns the formula, who buys the ingredients, and what a test run must prove before you search. If the formula is still open, close it first. On the NXTCPG process, "Formulate and source it" joins the sensory target, ingredient system, production path, and unit economics. Plant choice is part of that path, not a substitute for the formula.
How to evaluate a co-packer
Capabilities and equipment. Match the plant to the format you will make. Ask which lines run it, which steps stay on site, which steps move to another facility, and what the line cannot do.
Minimums. Ask the minimum order, the minimum run time, and what happens to short runs and leftovers. Get the unit — cases, kilograms, hours, or dollars. Use this plant's number for this SKU. There is no universal minimum to copy.
Certifications and audits. Ask which certifications the site holds, who issued them, the audit date, and whether the scope covers this process. Ask if you may audit, or send a qualified auditor, before you commit production.
Food-safety plan. Where subpart C applies, ask who the preventive controls qualified individual is and whether you can review the hazard analysis and preventive controls for your product, allergens, and sanitation. For a supplement, ask how the plant meets Part 111. Ask how allergens are segregated and how the label is checked against the formula.
Who sources ingredients. You can deliver them, the plant can buy to your specification, or the plant can supply its own, which is closer to private label. Ask who may approve a substitute and who pays for a rejected lot. Sourcing and co-manufacturer selection stay separate in Source & produce unless the agreement joins them.
Scheduling and capacity. Ask where the run sits, how changeovers are ordered, and what happens if the prior run overruns. Get that in writing before a quote counts as capacity.
Pricing structure. Ask the quote to separate the packing or processing fee, ingredients if the plant buys them, packaging, changeover, testing, storage, and yield loss, and which charges appear only after the first order. A low fee with an opaque ingredient markup is not a low cost.
Formula ownership and confidentiality. Sign a confidentiality agreement before you send a formula, a target cost, or a customer list. Ask who owns the formula, process parameters set on the line, and improvements the plant proposes, whether the plant may run the same formula for another brand, and who owns custom tooling and leftover packaging. Silence is not agreement.
Pilot and test runs. Trial on the equipment that will make the commercial lot. Agree beforehand what you will check — appearance, fill, code date, allergen changeover, and a retained sample — plus who attends, who pays, and what a pass is. A trial that cannot fail is a tour.
Red flags
Pause if the plant will not say whether it manufactures, packs only, or supplies the formula, or will not discuss registration, the applicable food-safety rule, or audit scope. Pause if a registration number is offered as FDA approval. Section 1.242 says that number does not convey approval or endorsement. Also pause if you cannot approve an ingredient substitute, if the quote is a single number, or if the plant owns your formula or line improvements unless the clause is changed. Pause if there is no commercial-line trial, if that trial has no pass standard, or if capacity is called open and the schedule is withheld. None of this is a final verdict on the plant. It means you cannot manage the relationship yet.
Where this sits with NXTCPG
Choosing a co-packer sits in Source & produce, with ingredient sourcing, co-manufacturer selection, COGS and margin architecture, and quality and scale readiness. It belongs on the process after the commercial opening is clear and beside the formula. If the quote skips who makes, who packs, who buys, and who owns the formula, start a project.
FAQ
What do co-packer and co-packing mean?
In commercial use, a co-packer packs your product into the consumer format under your brand. Co-packing, also called co-packaging or contract packaging, is that work. The plant may also manufacture. FDA does not define the nicknames. In 21 CFR 117.3, manufacturing/processing examples include packaging, bottling, and labeling, while packing means "placing food into a container other than packaging the food" and also includes re-packing.
How is a co-packer different from a co-manufacturer and from private label?
A co-manufacturer makes the product, usually to your formula or one you develop together, and often packs it. A co-packer may only pack, or it may manufacture too. Private label means you brand a formula the manufacturer already owns. Plants use the words loosely. The agreement has to name the activities and who owns the formula.
Does an FDA registration number mean the co-packer is approved?
No. 21 CFR 1.242 states that assignment of a registration number means the facility is registered with FDA and does not in any way convey FDA's approval or endorsement of a facility or its products. 21 CFR 1.226(g) exempts facilities regulated exclusively, throughout the entire facility, by the U.S. Department of Agriculture under the Federal Meat Inspection Act, the Poultry Products Inspection Act, or the Egg Products Inspection Act from this registration subpart.
What should we lock before a pilot run?
Lock who owns the formula, who owns process changes made on the plant's line, whether the plant may make that formula for another brand, and who owns custom tooling and leftover packaging. Sign a confidentiality agreement before the formula is sent. Agree what the pilot must show on the commercial line, and what a pass is, before it is scheduled.
Who should buy the ingredients?
Decide it on purpose. You can supply them, the plant can buy to your specification, or the plant can supply its own specification, which moves the deal toward private label. The choice changes cost, who may substitute a lot, and what you can stand behind on the label.