This is what a buyer checks before they shortlist automotive, rail, marine and aerospace suppliers.
What does a Tier 1 or OEM buyer check before sourcing a new part from you?
They check your IATF 16949 status with the certificate number, the PPAP level you can submit, and whether you have process capability evidence. Automotive sourcing is a documented process, and a supplier who cannot show the documents cannot enter it whatever the part costs.
A sourcing engineer is assembling a bidder list that has to survive a supplier quality review.
Last corpus review: 4 August 2026 · Written for automotive component manufacturers selling to business buyers
What does a Tier 1 or OEM buyer check before sourcing a new part from you?
What buyers check in automotive, rail, marine and aerospace
Three things, in order: what the product is, what the paperwork proves, and when each document gets asked for.
The automotive quality system, with certifi…
IATF 16949 certificate
Asked at: the first gate — usually before any technical review
That you can produce the production part ap…
PPAP submission capability with level
Asked at: sourcing decision
Formal declaration that parts meet requirem…
Part Submission Warrant
Asked at: part approval
First, what the product is
The fields a buyer scans before deciding whether you are worth contacting. Missing one of them usually ends the visit without an email.
- 1
Part families and processes
The buyer matches their commodity to your process route.
- 2
Materials and grades
Determines feasibility and validation route.
- 3
Annual capacity per part family
Programme volumes are fixed; your capacity has to meet them.
- 4
Tolerance and process capability
Cpk expectations are explicit in automotive.
- 5
Tooling capability and ownership
Decides timeline and investment structure.
- 6
Customer segments already supplied
Tier 1, OEM and aftermarket are different qualification regimes.
- 7
Plant locations
Proximity and dual-sourcing are real sourcing criteria.
Then the paperwork
Naming the documents you can issue is what separates a supplier who can be audited from one who cannot.
| Document | What it proves | Where it belongs |
|---|---|---|
| IATF 16949 certificateAsked at: the first gate — usually before any technical review | The automotive quality system, with certificate number and certification body | Publish it |
| PPAP submission capability with levelAsked at: sourcing decision | That you can produce the production part approval package the customer requires | Publish it |
| Part Submission WarrantAsked at: part approval | Formal declaration that parts meet requirements | Per shipment |
| Control plan and APQP evidenceAsked at: supplier quality assessment | That quality is planned into the process, not inspected in | Name it, share on request |
| SPC and Cpk dataAsked at: technical review | Demonstrated process capability on the characteristics that matter | Name it, share on request |
| IMDS submission capabilityAsked at: onboarding | Material data reporting into the automotive industry system | Publish it |
| Run-at-rate or capacity studyAsked at: before programme award | That the quoted volume is achievable at the quoted quality | Name it, share on request |
The shortlist moment
A buyer lines up a few suppliers and keeps the ones whose proof is easy to check. The rest get a closed tab, not an email.
The buyer asks: What does a Tier 1 or OEM buyer check before sourcing a new part from you?
A few suppliers get compared side by side:
A supplier with IATF 16949 certificate on the page
The automotive quality system, with certificate number and certification body
A supplier with PPAP submission capability with level on the page
That you can produce the production part approval package the customer requires
A supplier with IMDS submission capability on the page
Material data reporting into the automotive industry system
Is one of them you?
What Plact does for automotive, rail, marine and aerospace suppliers
Four jobs, done on your site. Each one is a document buyers in this industry already ask for.
Put the IATF 16949 certificate on the page buyers check
The automotive quality system, with certificate number and certification body
Put the PPAP submission capability with level on the page buyers check
That you can produce the production part approval package the customer requires
Put the IMDS submission capability on the page buyers check
Material data reporting into the automotive industry system
Name the Control plan and APQP evidence and share it on request
That quality is planned into the process, not inspected in
What a useful enquiry looks like
A form that collects these fields can be answered properly the first time. A form that collects a name and a message cannot.
Enquiry form · auto components
Enough to reply usefully, short enough that a buyer finishes it.
- Part drawing and customer part number
- Everything downstream depends on it.
- Material and specification
- Determines process route and validation.
- Annual volume and programme life
- The basis of the whole commercial case.
- PPAP level required
- Drives cost and timeline of onboarding.
- Tooling status
- New, transfer or customer-owned changes the project.
- SOP date
- Start of production is the fixed point everything works back from.
An enquiry from this search asks for
- Part drawing and customer part number
- Annual volume and programme life
- SOP date
- Material and specification
Questions suppliers ask
Should the IATF certificate number be published?
Yes, along with the certification body and the site it covers. Automotive buyers verify certification against the public IATF database as a matter of routine, and giving them the number is simply removing a step from a check they will perform anyway.
We supply the aftermarket, not OEMs. Does this still apply?
Partly. Aftermarket buyers care less about PPAP and more about fitment data, cross-references to OE part numbers, packaging and warranty. Publish the cross-reference table — it is the single most valuable page an aftermarket supplier can have.
How do we show capability without naming customers under NDA?
Describe the commodity, the process, the tolerance held, the annual volume and the segment, without the customer name. Sourcing engineers are assessing whether you have done work of that type at that level, and that can be established without breaching an agreement.
Documents and standards named here are the ones buyers in this industry commonly ask for; requirements vary by market, customer and contract, so treat this as a starting checklist rather than a compliance list. Clearer pages can help discovery and evaluation. They do not guarantee rankings, AI citations, enquiries or revenue.
Plact Research. Plact's editorial desk for buyer-evidence research. Industry standards, documents and buyer questions are researched and drafted with Plact's AI tools, then reviewed by Praveen Kavuri before publication. Every claim cites the standard, regulation or public source it rests on.
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