How do I add seats to my DevOps subscription?

Symptoms:

• I need to increase the number of seats on my DevOps subscription.
• How do I add people to DevOps?

Cause:

Unlike legacy Plastic SCM offerings, Unity DevOps charges per seat rather than 'active user'. Unity DevOps offers up to three seats for free. Any number of seats added to your subscription over three are charged for every month. 

Resolution:

To add seats to your Unity DevOps subscription, follow the steps below:

1. Navigate to dashboard.unity3d.com, and sign in using your Unity ID credentials. 
2. Select DevOps on the left-side menu.
   
3. Using the left-side menu, select Version Control to open the drop-down menu > select Settings.
   
4. In the Organization settings window, select Billing.
   
   
5. Under the Manage seats section of the page, select the pencil icon.
   
6. Using the upward arrow (🔼), add the number of seats you need > select Save.
   
7. A pop-up window appears. select Confirm to immediately apply your changes.
   

Your new DevOps seats are ready to be assigned.

More information:

How do I sign up for Unity DevOps?

How do I invite members to my Unity Version Control System (UVCS) organization?
How do I add concurrent builds under DevOps?