Knowledge Base

What is a Method of Communication (MOC) for callback validation?

Updated on August 24, 2026

Overview

By reading this article you will be able to identify which telephone number or email address Sectigo can use to confirm your certificate request, and what to do when no verified detail is available. It explains what a Method of Communication (MOC) is and why the Certification Authority (CA)/Browser Forum requires one; the two approved method types; the difference between automated and manual callback and which certificate types use each; the approved sources a detail must appear in — a Qualified Independent Information Source (QIIS), Qualified Government Information Source (QGIS), Qualified Government Tax Information Source (QTIS), or Verified Professional Letter; and the five pre-constructed email addresses Sectigo also accepts.

What is a Method of Communication?

A Method of Communication (MOC) is a verified telephone number or email address associated with the Applicant, used to confirm that a certificate request is authentic. Validating the authenticity of a certificate request is a step mandated by the Certification Authority (CA)/Browser Forum, and it must be carried out using a reliable Method of Communication. The detail must be established from an approved validation source, must be clearly associated with the Applicant, and must be current.

In the Sectigo validation process, this confirmation step is referred to as callback validation. You may also see it called order authorization or signer verification — this article uses callback validation throughout.

Important: A personal or work telephone number or email address cannot be used for the callback step unless it has been verified through a Sectigo-approved validation source, or confirmed by contacting the Applicant through an already verified Method of Communication.

Approved method types

Sectigo currently accepts two Method of Communication types:

Telephone numbers
Email addresses

Callback processes by certificate type

The callback process depends on the certificate type being issued.

Process	Applies to	Telephone number used	Email address used
Automated callback	Organization Validation (OV) certificates only	The Applicant receives an automated email at the Admin email address and can place an automated call to the verified telephone number entered by the Sectigo validation team to complete the callback.	The Applicant receives an email at the verified address containing a verification code and instructions to complete the callback.
Manual callback	All Extended Validation (EV), Document Signing, and eIDAS/Qualified certificates	Sectigo places a manual call and must confirm the certificate request details with the Contract Signer directly. If Sectigo cannot speak with the Signer, a reference code is left with the phone operator and the Contract Signer calls Sectigo back with that code to complete the validation.	Sectigo sends a signer verification email to the verified address containing the certificate request details, including the Contract Signer information. The Applicant must reply to the email with their confirmation.

Two points to note:

The automated callback option also allows the Applicant to request a manual callback or schedule a callback for a later time.
For Organization Validation (OV) level certificates, Sectigo is not required to speak with the Signer or Admin directly — any authorized individual can confirm the certificate request details.

Approved sources for a Method of Communication

A telephone number or email address qualifies only if it appears in one of the following sources.

Source	What it is
Qualified Independent Information Source (QIIS)	A third-party database or information provider that has been evaluated and approved by Sectigo as a reliable source of independently verified information.
Qualified Government Information Source (QGIS)	A government-operated database, registry, or publication that provides authoritative information about an organization's legal existence, registration status, licensing, or other government-maintained records.
Qualified Government Tax Information Source (QTIS)	A government-operated source that provides tax-related information about an organization or an individual.
Verified Professional Letter	A written attestation issued by a qualified professional — an attorney, a Certified Public Accountant (CPA), or a Latin notary — and verified in line with Sectigo requirements. Used in rare cases where none of the sources above are available.

For the full Verified Professional Letter requirements, see the related article listed at the end.

Pre-constructed email addresses

Sectigo also accepts one of the five pre-constructed email addresses authorized by the Certification Authority (CA)/Browser Forum, provided the domain is listed in a Qualified Independent Information Source (QIIS), Qualified Government Information Source (QGIS), or Qualified Government Tax Information Source (QTIS) document:

Figure: Screenshot of example email ids

What to do if no verified detail is found

If Sectigo cannot find a verified telephone number or email address in any approved source, the Applicant must make a source available so the requirement can be met. The source must be Sectigo-approved. Contact the Sectigo validation team to confirm that a source is acceptable before using it.

Sectigo does not recommend any specific third-party source. Choosing a source is the Applicant's decision, provided it meets the qualifications listed for that source type in the table above.