A few NU Departments have a general phone number, but the number is not found by searching in the Calls section of Teams.  For example, the IT Help Desk phone number (425.889.5310) cannot be found in the Contact list.    
  
See the Employees by Department Directory (sign in required) for the current phone list.  

It is easy to add new numbers to your Contacts list:    

• Open the Contacts tab in Calls and click the Add contact button.    
• Type desired name for the contact, ignore any suggestions that pop up (press Esc), and then click the Add button.   
• Enter the Phone number and click the Add button.      

To Call the Contact You Added:      

Open the Contacts tab in Calls and use the Find a contact box to search for the contact you added.      

Add the Contact to your Speed Dial list:      

Find the contact you added to your list, click on the three dots, and select Add to speed dial.  

Resources: 
View or Add Contacts in Teams (Microsoft)   
Employees by Department or by Name (Northwest University Directories – sign in required)