Microsoft 365 by default allows end users to request new licenses and, currently in 27 cases, to purchase licenses with their own credit cards, sometimes with a trial first. As an admin, I prefer to manage licenses directly and not have users wasting their time and even their own money playing with random, potentially expensive products that may not even apply to their jobs.
Redirect License Requests
I don’t see a way to completely turn off license requests, but you tell M365 to “use your own request process,” which will advise users to contact their system admin about licensing.
In the admin center, go to Billing > Licenses, click on the Requests tab, click on Connect your request process, check Use my organization’s request process, fill in a Message, and click Save:
The Microsoft doc on managing self-service requests is here.
Turn Off Self-Purchase Licenses
You can view the self-service purchase status of all products from Settings > Org Settings > Services > Self-service trials and purchases. However there are currently 27 products and that page only allows you to disable them individually. To disable all of them at once, you’ll need to use PowerShell. From this article (test and use at your own risk!):
Install-Module MSCommerce
Connect-MSCommerce
# List all products and their self-service statuses
Get-MSCommerceProductPolicies -PolicyId AllowSelfServicePurchase
Get-MSCommerceProductPolicies -PolicyId AllowSelfServicePurchase | ForEach {Update-MSCommerceProductPolicy -PolicyId AllowSelfServicePurchase -ProductId $_.ProductId -Enabled $False}
# List all products again. Confirm that their self-service statuses are disabled
Get-MSCommerceProductPolicies -PolicyId AllowSelfServicePurchase
After running those commands, the result shows all policies disabled:
Note that this list of products will probably grow and that new products will default to Enabled, so you’ll have to review and update these policies periodically.
Microsoft docs on managing self-service purchases are here and here.