USB Product Certification FAQ

Membership & test process related issues 

1. How do you become a USB member? 

 If you want to obtain USB certification, you or your customer (brand company) must have a USB VID (Vendor ID) and obtain a website account password for product registration. Apply for Vendor ID URL ( )

Refer to the USB certification process


2. How is the USB logo used? 

 If your company’s product has passed the test and got the product TID , you also need to sign a Trademark License Agreement with the USB-IF to use the USB Logo.

For detailed USB Logo usage specifications and contract signing, please refer to: .


3. How do I confirm / inquire about products with USB TID? 

 If you want to inquire / confirm whether you have got a TID product, you can search it in the Integrator List on the USB-IF Association website

*You need to log in as a USB member to enter this page.


4. The product has passed certification and obtained TID, can I resell it to other manufacturers for use?

 If the following conditions are met, OEM Arrangements can be carried out and resold.

  • The buyer needs to be a member of the USB Association
  • The buyer needs to sign the USB-IF Trademark License Agreement

For details, please refer to: ( content of OEM Agreements )


5. If there is a Family Model, what can I do?

 USB-IF can apply for QbS (Qualification by Similarity) for specific modifications, please refer to the USB-IF website for the degree of modification

QbS application: QbS application link


6. What is the duration of the USB Vendor ID (VID)?

The USB VID is valid for life, even if your membership has expired, the VID is still valid


USB4 certification related issues

1. If the certification has passed USB4 certification, then does it need to pass Thunderbolt certification?

If the product is USB4 supporting Thunderbolt compatible, you only need to obtain USB4 certification, and you do not need to obtain Thunderbolt 3 certification. However, if you want the product to declare Thunderbolt certification or use the “Thunderbolt 3” logo, you need to obtain Thunderbolt certification separately.


2. Is it necessary to obtain USB4 certification, does it need to pass Thunderbolt 4 certification ?



3. Do USB4/TBT3/TBT4 certifications still have to be submitted separately?

The USB4 logo belongs to USB-IF; Thunderbolt 3 and Thunderbolt 4 logo belong to Intel. They belong to different organizations, so submit them separately.


4. Thunderbolt 3 Compliance pass indicate USB 4 Compliance pass?

 It’s not. TBT3 only tests EV (electricity) and FV (compatibility), but USB4 contains more, please refer to USB4 test items


5. Can GRL teach customers on how to conduct USB4 testing?

Please contact GRL Email:


Product testing related issues

1. Which USB Legacy Connector products can be certified? 


2. Which USB Legacy Cable products can be certified? 

The data wire gauge association of Standard A to Micro B and standard A to Standard B cable must be 28AWG


3. Is there any length limit for  USB Legacy Cable certification 



4. Which USB Type-C to Type-C Cable can be certified and precautions? 

USB Type-C to Type-C Precautions chart


5. What USB Legacy to Type-C of the cable can be certified? 

USB Type-C Version Certification



6. What USB accessory can be certified? 

*Note:2.0 C to Micro B Adapter does not need to be wired3.2 C to Standard A Gen1 Adapter must be wired
USB Accessory Certification Chart


7. Can the special cable/architecture pass the USB certification?

  • Type-C cable with LED lights
  • Tilted Head Type-C cable
  • Flat wire/telephone wire

Please contact us for other special products


8. Products whose special Connector/architecture cannot pass USB certification

  • Standard A+ Type-C Double Connector
  • Apple charging cable

Please contact us for other special products


9. What are the preparation for USB Embedded Host testing?

When any product is being tested, it needs to enter the test mode before the test can be performed.

  1. The recommended way to enter test mode using USB-IF, please refer to the USB-IF page  (see the figure below for the reference paragraph).
  2. If you do not sue the method recommended by the association, please provide it to GRL when you send it for testing.


10.Can a Type-C connector be certified?

There are EMC pads inside the product

  • There are shrapnel above and below the iron case
  • Shrapnel on one side, convex hull on the other
  • The top and bottom of the iron shell are convex hulls, and the distance between the convex hulls must be greater than the thickness of the plug iron shell
  • The top and bottom of the iron shell are convex hulls, and the distance between the convex hulls must be greater than the thickness of the plug iron shell

There is no EMC pad inside the product

  • There is no shrapnel above and below the iron case
  • Shrapnel on one side, convex hull on the other

Please contact us for other special products

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This information is provided for reference only. This information is not and should not be regarded as an official communication of the USB Implementers Forum (USB-IF). The official communication of USB-IF can be obtained from its website or directly from USB-IF.