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BIMI and VMC Certification · Common Mark Certificates

How to set up Common Mark Certificates (CMC): step-by-step guide (2026)

Short answer

To set up Common Mark Certificates (CMC): Document at least 12 months of logo use (Wayback Machine snapshots, marketing materials); Prepare the logo as SVG Tiny PS; Complete organization validation with DigiCert or Entrust. Then publish the certificate URL in the a= tag of your BIMI record.

It opens BIMI in Gmail to small businesses and new brands that cannot afford or have not completed trademark registration.

How to implement Common Mark Certificates (CMC)#

  1. Document at least 12 months of logo use (Wayback Machine snapshots, marketing materials).
  2. Prepare the logo as SVG Tiny PS.
  3. Complete organization validation with DigiCert or Entrust.
  4. Publish the certificate URL in the a= tag of your BIMI record.

How to verify it worked#

Send a test message to seed mailboxes at Gmail, Outlook, and Yahoo, then inspect the Authentication-Results and delivery headers. Repeat after any DNS or sending-platform change.

Common mistakes#

  • Expecting the blue checkmark; CMC does not qualify.
  • Changing the logo after issuance, which invalidates the certificate.

Frequently asked questions#

Which providers accept CMC?

Gmail accepts CMC as of 2024. Apple accepts VMC and CMC. Yahoo does not require a certificate.

Can I upgrade from CMC to VMC?

Yes, once the trademark registers. Reissue the certificate and update the a= tag.

Keep reading on Common Mark Certificates