Introduction
This article will try to explain the concept of RTU licensing model used on 3504, 5520 and 8540 Wireless LAN Controller (WLC) by answering most common questions Cisco TAC receives from customers. All the commands and screenshots are collected on 3504 WLC running 8.8.100.0 image.
Q. What type of licensing exists on 3504 Wireless LAN Controller?
A. 3504, 5520 and 8540 Wireless LAN Controllers supports 2 types of licenses:
- RTU (Right-To-Use) Licensing
- Smart-Licensing
This article only explains RTU licensing. Information about smart licensing deployment can be found HERE.
Q. How does RTU licensing model work?
A. RTU (Right-to-use) licensing model (with End User License Agreement acceptance) is an honor based licensing model created for faster and more flexible network deployments. For every AP joined to the controller, one license count is required.
Unless licenses are built in, they can be freely transferred between controllers (with some limitations, described later in the article). With RTU model, 3504 WLC supports up to 150 access points, 5520 WLC supports 1500 and 8540 WLC supports up to 6000 access points.
Note: RTU licensing is available starting 8.5 release
Q. How do I select which type of Licensing is used?
A. In the controller web interface, navigate to Management->Software Activation->License Type and from the drop-down menu set the Licensing Type to be RTU. Press Apply to save the settings.

Alternatively, it can be done from the CLI using following command (reboot is required):
(Cisco Controller) >config licensing rtu
Changing the licensing model requires a reboot of the WLC (Manually).
Are you sure you want to continue ?(y/n)
Q. How do I add (activate) and remove AP licenses?
A. Under Management->Software Activation->Licenses from the dropdown menu select "Add", enter the amount of licenses that you want to add and press "Set Count". An End User License Agreement window will pop. You have to accept it every time you wish to add/delete licenses. Full EULA can be found HERE.
Important: You are only allowed to add the exact amount of licenses you have purchased. Cisco is entitled to confirm that your access point enablement is properly licensed.

After you accept, the permanent licences will be added. This type of license is commonly know as AP adder license. If you choose Delete from the drop down menu, licenses will be deleted.

Alternatively, licenses can be added/removed from the CLI using following commands:
(Cisco Controller) >license add ap-count <number_of_licenses>
(Cisco Controller) >license delete ap-count <number_of_licenses>
Q. Where do I download the license file?
A.License files do not exist on3504 (nor on 5520/8540) WLC. You simply have to add the amount of licenses that you have bought.
Q. How do I install license file?
A.There is no license file nor license file installations on 3504 (nor on 5520/8540). Licenses simply have to be added.
Q. Where do I download licenses for special features?
A. There are no special features that require licenses. One license is required for every AP that is joined to the controller.
Q. What is evaluation (ap_count) license?
A. Evaluation license is a demo/trial license meant to be used during the deployment of the network and testing phases. It expires after 90 days. The EULA states that you are obligated to pay for the specified license count within 90 days of usage. Evaluation license comes with the controller and cannot be deleted. Once you add permanent licenses, evaluation license status will simply change to "inactive".
Note: Cisco TAC recommends to add permanent AP licenses as soon as possible.
Q. Are licenses tied to a wireless controller?
A. When purchasing WLC and Access Point licenses, there are 2 options:
- Buying controller with licenses built-in
- Buying controller and licenses separately
If your AP licenses are bought separately, you can freely transfer them between any two 3504, 5520 or 8540 Wireless Controllers.
If your AP licenses are built into the controller, you will not be able to transfer them. EULA mentions that as well:

You will not be able to delete them. Not even factory reset or image upgrade can change this.
TAC support will not be able to help you in this situation. The best way to solve the issue is to contact your account manager or sales team, they will be able to assist you.
Note: Cisco TAC recommends buying controller and licenses separately. This provides a lot more flexibility and allows licenses to moved in the future.
Q. Can I transfer licenses between 3504, 5520 and 8540 WLCs?
A. Yes, you can freely transfer licenses between any two 3504, 5520 or 8540 controllers. To do that, just remove the desired amount of AP licenses from one and add the same amount to another.
Q. Can I transfer licenses between 3504/5520/8540 and other older controllers (e.g. 2504, 4400, 5508, 7510, 8510)?
A. No, you are NOT allowed to transfer AP licenses between 3504/5520/8540 and older controllers like 2504/4400/5508/7510/8510.
Q. My license status says that it is "Active, Not-In-Use". Why?
A. If a license status is active, but not it use, it means that license is active, but there are no AP joined to that controller that are using said license. Once the AP joins to the controller, the status of the license will be changed to "Active, In Use".
Q. Where can i see the amount of used and remaining licenses?
A. In the controller web interface under Management->Software Activation->License statistics, you can see total, used and remaining AP license counts:

This can also be done from the controller CLI using the following command:
(Cisco Controller) >show license capacity
Licensed Feature Max Count Current Count Remaining Count Remaining Capacity
----------------------------------------------------------------------------------------------
AP Count 10 2 8 148/150
Q. I am unable to delete licenses: error "Failed to decrease adder license count". How do I fix it?
A. This error will pop up only when you are trying to delete the licenses that are built into the controller at the time of purchase. Not even factory reset or image upgrade will change this. Cisco TAC support will not be able to help you in this situation. Contact your account manager or sales team, they will be able to assist you.
Q. Is there a minimum amount of licenses required to enable HA SSO between 2 WLCs?
A. No. Unlike older controllers, 3504, 5520 and 8540 WLC can establish HA SSO even with only 1 AP license installed.
Q. I have two WLCs without built-in licenses and I want to run them in High Availability (HA). How do I add the licenses?
A. After establishing the HA, total number of licenses will be equal to the number of licenses on primary controller. After that, simply go to Management->Software Activation->Licenses in the web interface and add the additional amount of licenses you have purchased.
Q. I have two WLCs with built-in licenses and I want to run them in HA mode. How do I add the licenses?
A. Example: One controller (intended to be primary) has 40 built-in licenses, the other (intended to be secondary) has 20 built-in licenses. Once you establish the HA SSO between them, built-in license count will be equal to the number of licenses on the primary controller, in this example 40. Simply add the remaining 20 licenses to the controller.
Q. I already have two WLCs running in HA mode. I have purchased additional AP licenses. How do i add them?
A. Simply add the amount of licenses you have purchased in the web interface of the primary controller under Management->Software Activation->Licenses.
Q. How does licensing work in N+1 High Availability mode?
A. Simply add the amount of licenses that you have purchased to all controllers. There will be no license violation as long as the number bought licenses is higher or equal to the total number of joined APs on all controllers in N+1 High Availability.