How to check a PCB manufacturer's UL certification
Question this page answers
How can I verify a PCB manufacturer's UL certification?
Step-by-step UL verification for PCB buyers: find the E-number, confirm the certificate holder and match the recognised factory address.
The short answer
Do not accept a logo or a certificate scan. Look up the UL file number in UL Product iQ, then confirm that the certificate holder and the recognised manufacturing location both match the entity that will produce your boards.
Step 1 — Get the exact file number
Ask for the UL E-number (or the full file number) as printed on the marking, not a certificate title. Note which product category it covers: a recognition for one laminate or board construction does not automatically extend to every stack-up the factory offers.
Step 2 — Look it up in UL Product iQ
Search the number in UL Product iQ (iq.ul.com). Check the applicant or manufacturer name, the file status, the recognised location and the scope of the recognition. Record the date you performed the check.
Step 3 — Match three names
Compare the UL applicant name with (a) the Chinese registered legal entity from the business registry and (b) the name on the quotation and invoice. Three different names are common in export transactions, but you need to know which one carries the certification.
Step 4 — Match the address
The recognised factory address in the UL record should match the production site. A head office, a bonded warehouse or a sister plant is not the same thing. If the supplier says production happens at a different site, ask which UL file covers that site.
Step 5 — Re-check before a repeat order
Certification status and recognised locations change. Note the review date on your supplier record and check again before a new product family or a long gap between orders.
ChinaPCB links to the underlying public record from a factory profile and keeps those links followable, so a buyer can repeat the check independently.
Sources and review
The public registries and certification databases named on this page are the primary sources we use. Every fact on a ChinaPCB factory profile is accompanied by its source and the date it was last checked. Where a claim could not be checked, the field is left unconfirmed instead of being filled with an estimate.
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About the author
ChinaPCB Editorial. ChinaPCB.org is an editorial directory operated by Weis Technology Co., Ltd.. Its operating entity and correction channel are published openly, and every factual claim on a factory profile carries an evidence level and review date.