Certificate Security2026-04-025 min read

What are CAA records?

Learn what CAA records do, how they restrict certificate issuance, and why they are useful for certificate governance.

Introduction

CAA stands for Certification Authority Authorization. A CAA record lets a domain owner say which certificate authorities are allowed to issue certificates for the domain.

This is a useful control for reducing the risk of unintended certificate issuance.

Common CAA tags

  • issue authorizes standard certificate issuance
  • issuewild authorizes wildcard certificate issuance
  • iodef provides a contact or reporting destination for policy violations

Why CAA matters

CAA records add a policy layer around certificate issuance. They are not mandatory, but they are a useful hardening control.

They are especially useful for organizations that want clearer control over which CAs can issue for their domains.

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