How to Track COGS When You're Using a Co-Packer

If you're a CPG founder working with a co-packer, you already know the drill: you send them your raw materials (or they source them), they produce your product, and you get an invoice that bundles everything together in a way that makes your bookkeeper's eye twitch.

Tracking your cost of goods sold accurately when a co-packer is in the picture is one of the trickiest parts of CPG accounting — and one of the most important. Your COGS number drives your gross margin, which is the single metric investors, buyers, and lenders look at first. Get it wrong, and you're either overvaluing your business or leaving money on the table.

Here's how to get it right.

Why Co-Packer COGS Gets Messy

When you manufacture in-house, tracking COGS is relatively straightforward. You buy ingredients, you pay labor, you account for overhead, and you assign those costs to each unit produced.

With a co-packer, things get complicated fast. Your co-packer might lump raw materials, labor, packaging, and fulfillment into a single line item — and if you book that whole invoice as COGS without breaking it apart, your cost-per-unit data is useless. On top of that, you might be supplying some ingredients while they source others, so costs are hitting your books from two different directions. Then there's volume-based pricing tiers where your per-unit cost drops mid-run, and waste or overruns that need to land somewhere.

Step 1: Break Down the Co-Packer Invoice

Don't just book the invoice total to a single COGS account. Work with your co-packer to get an itemized breakdown, or create one yourself based on your agreement. At minimum, separate out raw materials/ingredients, packaging materials, co-packing fees (labor and overhead), and freight.

Each of these should map to its own sub-account under COGS in your chart of accounts. In QuickBooks, it might look like:

• 5000 — Cost of Goods Sold
• 5010 — Raw Materials / Ingredients
• 5020 — Packaging
• 5030 — Co-Packing Fees
• 5040 — Inbound Freight
• 5050 — Outbound Freight

This structure gives you actual visibility into where your money goes — and makes it much easier to spot when a cost creeps up.

Step 2: Account for Ingredients You Supply

If you're sending your own ingredients to the co-packer, those costs need to flow through your books correctly. You purchase the ingredients (hits inventory as an asset, not COGS). You ship them to the co-packer (still your inventory — some founders create a sub-account like "Inventory — At Co-Packer" to track this). The co-packer produces finished goods (ingredient cost combines with co-packing fees and packaging to become finished goods inventory). You sell the product (only now does the cost move to COGS).

The mistake most founders make is expensing the ingredient purchase immediately as COGS. That inflates your costs in the month you buy ingredients and understates them in the month you actually sell. Your monthly P&L becomes unreliable.

Step 3: Calculate Your True Cost Per Unit

Once you've broken everything down, calculate a real cost per unit for every production run:

Cost per unit = (Raw materials + Packaging + Co-packing fees + Freight in) ÷ Units produced

Keep a simple log that tracks each production run date, units ordered vs. produced, total cost by category, and cost per unit. Over time, you'll see if costs are creeping up, if certain SKUs are more expensive, and whether it's time to renegotiate.

Step 4: Handle the Edge Cases

Free fills and samples. Those units still cost money to produce. When you give them away, the cost moves out of inventory as a marketing or promotional expense, not COGS — since there's no corresponding revenue.

Damaged or rejected product. If the co-packer is at fault per your agreement, they should credit you. If it's your loss, book it as inventory shrinkage — a separate line from standard COGS so it doesn't distort your per-unit economics.

Price changes mid-contract. Update your cost-per-unit calculations going forward and note the effective date. Units produced before and after the change have different costs.

Step 5: Reconcile Monthly

At the end of every month, reconcile co-packer invoices against your production logs and inventory counts. Do the invoiced quantities match what you ordered and received? Does your inventory balance make sense? Are there unexplained variances?

This is tedious, but it's the difference between financial statements you can trust and ones that are rough guesses. When it comes time to raise a round or pitch a retail buyer, clean books aren't optional.

The Bottom Line

Your co-packer relationship is probably one of your biggest expenses. Tracking those costs accurately isn't just an accounting exercise — it's how you know whether your business is actually making money, where to cut costs, and how to tell your financial story with confidence.

If your books currently have a single line item that says "Co-Packer" with a big number next to it, it's time to dig in and break it apart. Your future investors (and your future self) will thank you.

Beck & Call Bookkeeping specializes in bookkeeping for CPG brands. If your co-packer invoices are giving you headaches, we can help you set up a system that actually makes sense. Get in touch →