How to Hand a Formula to a Contract Manufacturer Without Losing Control of It

What a co-packer actually needs from you, what you should never send, and how versioning, share links, and a batch record keep the formula yours while someone else makes it.

Published October 14, 2026 · By Formulate 360 Team· Topics: contract manufacturer cosmetics, co-packer formula, send formula to manufacturer, formula version control, batch record, private label skincare

The moment you send a formula to a contract manufacturer is the moment you stop being the only person who can make your product. That is the point, and it is also where most indie brands lose the plot: the formula goes out as a spreadsheet attachment, gets edited on both sides, and six months later nobody can say which version is in the jars on the shelf.

This is the handoff done properly. It is not complicated, but it has to be deliberate.

What a manufacturer actually needs

  • The formula by percentage, by phase, with the INCI name for every ingredient. Trade names help but INCI is the shared language.
  • The procedure: order of addition, temperatures, mixing, cool-down, where the actives go in, target pH and viscosity if you have them.
  • The batch size you expect and the unit size, so they can quote and plan.
  • Specifications for the finished product: appearance, pH range, viscosity range, anything you will reject on.
  • Your label copy and the INCI declaration in descending order, because they will often print or check it.

What you should not send

  • Your ingredient costs and margins. The manufacturer quotes on their own purchasing; your numbers only weaken your negotiating position.
  • Your supplier list, unless you want them to buy from those suppliers specifically. Most will source themselves.
  • An editable spreadsheet. Send a read-only view with a date and a version number on it. If they need a change, they ask and you issue a new version.
  • Anything you have not saved as a numbered version on your side first.
The version number is the contract: Every quote, sample, and production batch should reference a version number you control. When the manufacturer says “we made v4”, you need to be able to open v4 and see exactly what it contained, even if you are now on v9.

The handoff, step by step

  1. Freeze the formula as a version. Give it a note that says what it is for: “v3, sent to [manufacturer] for sampling”.
  2. Share a read-only link with an expiry date, costs hidden, and a password if the formula is sensitive. Email the link, not the file. If the relationship ends, revoke the link.
  3. Send the procedure with it. If your formula has process steps, they go in the same package.
  4. When samples come back, log your observations against the version: pH, viscosity, appearance, stability at elevated temperature. If you change the formula in response, that is a new version with a note explaining why.
  5. For production, issue a batch record: the version, the lot number, the scaled quantities for their batch size, the procedure, the QC checks you expect, and sign-off lines. This is the document that proves what was supposed to be made.
  6. When the lot is released, keep the record with their certificate of analysis. If there is ever a complaint or a recall, this is what you will be asked for.

Why a spreadsheet is not enough

Spreadsheets have no memory. You can overwrite v3 without noticing, you cannot see what changed between two sends, and a shared Google Sheet means the manufacturer's edits and yours collide. A formulation workspace keeps every version, shows the diff between them, lets you hand out time-limited read-only links, and generates the batch record from the version the batch was actually pinned to. That last part is the one spreadsheets really cannot do: the batch record must reflect the formula as it was when the lot was made, not as it is today.

CONFIRMED In Formulate 360 every save that changes the formula creates a version with a diff you can read; share links expire, can be password-protected, and hide costs by default; and a batch is pinned to the version it was made from, so the batch record PDF prints what was actually manufactured. Start free.

Quick answers

Should I give the manufacturer my full formula or only part of it?

For them to make it, they need all of it. What you control is the form: read-only, versioned, without your costs and suppliers. If you want a partial disclosure, you are looking at a split-manufacturing arrangement, which is a different conversation.

What if the manufacturer wants to substitute an ingredient?

That is normal and often sensible. Treat it as a change request: they propose, you decide, and if you accept it becomes a new version on your side before they make anything with it.

Do I need an NDA?

Usually yes, and a good manufacturer expects it. An NDA covers the legal side; versioning and revocable links cover the practical side. Use both.

How long should I keep batch records?

Keep them for the life of the product on the market plus the longest period in which a complaint could reasonably arrive. For many brands that means several years. Storage is cheap; not having the record is not.

Formulation assistance only. This article is general information, not legal advice, and not a substitute for review by a qualified formulator or regulatory professional.

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