SharePoint Online: Set Default Value for Multiple lines of text Field

Requirement: Set default value for multiple lines of text field in SharePoint Online.

How to set the default value for a multi-line text field?

The multiple lines of text field doesn't support "default" value through the web user interface. However, here is the trick to set the default value for multiple lines of text column.

• Open the SharePoint Online site in SharePoint designer.
• Navigate to your target list Click on "Edit list columns" link under "Customization"
• Double click on the multi-line text column of the list. In the "column editor" dialog box, you can set the default value for the column!
  

PnP PowerShell to Set default value for Multi-Line text column:

To set the default value for multiple lines of text field in SharePoint Online, use this PowerShell:

#Parameters
$SiteURL = "https://crescent.sharepoint.com/sites/pmo"
$ListName = "Projects"
$ColumnName = "Project_x0020_Description" #Internal Name
$DefaultValue = "Project Code: <<Enter the Project code >>, Project description: <<provide a detailed project description>>"

#Connect to Tenant Admin
Connect-PnPOnline $SiteURL -UseWebLogin

#Set Default Value for the field
Set-PnPField -Identity $ColumnName -List $ListName -Values @{DefaultValue=$DefaultValue}