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In this guide
When an at-home test kit program moves to a new manufacturer, most teams expect to carry the program across. What actually carries across is narrower: the specification, the approved artwork and the bill of materials, if you own them and if they are complete. The process validation, the work instructions, the fixtures and the trained people stay where they are. A new manufacturer starts from your documents, not from your old vendor’s floor.
That is why the transfer quote is rarely the real cost of switching. The cost sits in the gap between what your old vendor actually did and what your spec says they should do. Every undocumented habit has to be found, written down, and then kept or dropped on purpose: a desiccant added after one humid lot, a tube orientation the line settled on, a label placed a few millimeters higher to clear a fold. Your old vendor may not remember which of those were ever approved.
What moves with you and what stays
| Item | Who usually holds it | What to do before you give notice |
|---|---|---|
| Kit specification and BOM | You, if you wrote it | Reconcile it against the last lot actually built, not the last revision on file |
| Approved artwork, dielines and label files | You, if the contract says so | Get native files, not only PDFs, plus the approved proof record |
| Printing plates, cutting dies, custom tooling | Whoever paid, if it is in writing | Confirm ownership and arrange release, or budget to remake |
| Components and finished kits on hand | You, if you paid for them | Count, reconcile lots and expiry, arrange transfer |
| Work instructions and assembly procedures | The old manufacturer | Request kit-specific content as input; expect the new site to write its own |
| Process validation and inspection records | The old manufacturer | Plan validation at the new site |
| Build records for kits already shipped | The old manufacturer | Secure access for the full retention period |
| Line know-how | Nobody can transfer it | Capture it in a documented walk-through while the relationship is still working |
The build records row catches people. ISO 13485:2016 clause 4.2.5 requires records to be kept for at least the lifetime of the device as the organization defines it, and not less than two years from release. If your old vendor holds the only records for kits still in the field, losing access to them is a gap in your quality system, not theirs.
Why validation does not transfer
ISO 13485 clause 7.5.6 requires validation of any production process whose output cannot be verified by later monitoring or measurement. Validation evidence describes a specific process, on specific equipment, run by specific people. Move the process and the evidence now describes a process nobody is running. Your old vendor’s validation report is a useful reference for the new site. It is not a substitute for the new site’s own work, and the new site cannot validate a process it has not first developed on its own line (see You Cannot Validate a Process You Have Not Developed).
A validation report is evidence about a process. When the process moves, the evidence stays where it was.
How much new work that means depends on the kit. A kit that is fully inspected against the spec at final assembly carries a lighter burden than one with filling, sealing or labeling steps that cannot be checked without opening or destroying the product. Ask the new manufacturer which of your steps they will validate and which they will verify, and why. A clear answer is a good sign. “We will reuse your old report” is not.
The regulatory question belongs to the legal manufacturer
Since February 2, 2026, FDA’s Quality Management System Regulation (21 CFR Part 820) incorporates ISO 13485:2016 by reference. Under it, the company named as the device manufacturer evaluates and selects suppliers on their ability to meet requirements, with controls proportionate to risk (clause 7.4.1), and stays responsible for outsourced processes (clause 4.1.5). Changing kit manufacturers is a supplier change, and it runs through your change control before it runs through a purchase order.
Whether it also needs an FDA submission depends on the device’s pathway:
- PMA devices. 21 CFR 814.39(a)(3) lists the use of a different facility or establishment to manufacture, process or package the device among the changes that require a PMA supplement when they affect safety or effectiveness. FDA’s 2018 guidance on manufacturing site change supplements covers moving work to a contract manufacturer not already approved in the PMA.
- 510(k) devices. FDA’s 2017 guidance on deciding when to submit a 510(k) for a change does not address site changes directly. It asks whether a change affects labeling, technology or performance, or materials, and tells manufacturers to document the analysis when they conclude a new 510(k) is likely not required.
This is a regulatory determination. Make it with your regulatory lead or counsel, and make it before you sign with the new manufacturer, not after the first lot ships.
Build a bridge, then run both
The common failure looks like this. Notice goes out, the old vendor’s last build is sized to the notice period, the new vendor’s first lot slips by a month, and the program goes dark. Size the last build at the old vendor to the realistic transfer, not the contract.
An illustrative example: a program ships 400 kits a week. Onboarding and documentation take six weeks, first article and a pilot lot take four, and you hold four weeks of buffer for the slip that always comes. That is 14 weeks, or 5,600 kits of bridge stock. Then check dating. Bridge stock expires when its shortest-dated component does (see Your Kit Expires When Its Shortest-Dated Component Does), so a large last build can strand kits that cannot ship.
First article against the spec, not against the old kit
Compare the first kits from the new manufacturer against the spec and against retained kits from the old one. Where the two kits differ, the question is not which one looks right. It is which one matches the spec. If the old kit carried something the spec never mentioned, decide on purpose whether it goes into the spec or goes away.
Do not let the new manufacturer improve things quietly either. ISO 13485 clause 7.4.2 provides for a written agreement that a supplier notifies you of changes before they affect the product, and that agreement only protects what your spec defines (see Your Supplier’s Change Notice Only Covers What Your Spec Says). Then run a pilot lot through the whole chain: assembly, outbound shipping, the patient’s return and accessioning at the lab (see Specimen Return: From a Home Mailbox to Laboratory Accessioning).
Write the exit into the first contract
The hard part of any switch is what you cannot take with you, so settle it when the relationship starts. The first contract with any kit manufacturer should cover:
- Ownership of artwork files, printing plates, dies and custom tooling.
- Return of your inventory with a lot and expiry reconciliation.
- Access to build records for the full retention period.
- Transition support for a defined period: a walk-through of the line and answers to the new site’s questions.
- A notice period long enough to build a realistic bridge.
These belong on the list of questions to settle before you build anything with a partner (see What to Ask a Kit Fulfillment Partner Before You Build the Integration), and on any audit of your kit manufacturer.
A clean transfer is mostly a documentation exercise. The programs that move easily are the ones whose spec already described the kit the old vendor was actually building.
Sources: ISO 13485:2016, Medical devices: Quality management systems; FDA, Quality Management System Regulation (QMSR); 21 CFR 814.39, PMA supplements; FDA, Manufacturing Site Change Supplements: Content and Submission (2018); FDA, Deciding When to Submit a 510(k) for a Change to an Existing Device (2017).
