Manage Activation Code

Note:Tenable Nessus allows you to generate an activation code during the installation process. For more information, see Install Tenable Nessus Essentials, Professional, Expert, or Manager.

Tenable Nessus is available to operate either as a subscription or managed by Tenable Security Center. Tenable Nessus requires a plugin feed activation code to operate in subscription mode. This code identifies which version of Tenable Nessus that Tenable licensed you to install and use, and if applicable, how many IP addresses you can scan, how many remote scanners you can link to Tenable Nessus, and how many Nessus Agents you can link to Tenable Nessus Manager. Tenable Nessus Manager licenses are specific to your deployment size, especially for large deployments or deployments with multiple Tenable Nessus Manager instances. Discuss your requirements with your Tenable Customer Success Manager.

Tenable recommends that you obtain the activation code before starting the installation process, as it is required before you can set up Tenable Nessus.

Your activation code:

  • is a one-time code, unless your license or subscription changes, at which point Tenable issues you a new activation code. Alternatively, you can transfer an existing activation code to a different system. For more information, see Transfer Activation Code.
  • must be used with the Tenable Nessus installation within 24 hours.
  • cannot be shared between scanners.
  • is not case-sensitive.
  • is required to manage Tenable Nessus offline.

    Note: For more information about managing Tenable Nessus offline, see Manage Tenable Nessus Offline.

You may purchase a Tenable Nessus subscription through the Tenable, Inc. online store at or via a purchase order through Authorized Nessus Partners. You then receive an activation code from Tenable, Inc.. This code is used when configuring your copy of Tenable Nessus for updates.

Note: See the Obtain an activation code page for instructions on how to obtain and use an activation code.

If you are using Tenable Security Center to manage your Nessus scanners, the activation code and plugin updates are managed from Tenable Security Center. You must start Nessus before it communicates with Tenable Security Center, which it normally does not do without a valid activation code and plugins. To have Nessus ignore this requirement and start (so that it can get the information from Tenable Security Center), when you register your scanner, select Managed by SecurityCenter.

To manage your activation code, use the following topics: