Nessus Licensing Requirements

Nessus is available to operate either as a subscription or managed by Nessus requires a plugin feed Activation Code to operate in subscription mode. This code identifies which version of Nessus you are licensed to install and use, and if applicable, how many IP addresses can be scanned, how many remote scanners can be linked to Nessus, and how many Nessus Agents can be linked to Nessus Manager.

It is recommended that you obtain the Activation Code before starting the installation process, as that information will be required before you can authenticate to the Nessus GUI interface.

Additionally, your activation code:

  • is a one-time code, unless your license or subscription changes, at which point a new activation code will be issued to you.
  • must be used with the Nessus installation within 24 hours.
  • cannot be shared between scanners.
  • is not case sensitive.
  • is required to Manage Nessus Offline.

You may purchase a Nessus subscription through the Tenable Online Store at or via a purchase order through Authorized Nessus Partners. You will then receive an Activation Code from Tenable. This code will be used when configuring your copy of Nessus for updates.

Note: If you are using to manage your Nessus scanners, the Activation Code and plugin updates are managed from Nessus needs to be started to be able to communicate with, which it will normally 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, enter “SecurityCenter” (case sensitive) without quotes into the Activation Code box.

Please refer to the following link for the most current information on obtaining an Activation Code: