Telephone Links In SharePoint

There is a workaround that allows this to work by using JSON column formatting on a SharePoint list view. I came across this article and worked with Copilot to adjust it for tel: links instead of https links. We use Teams phone, and I was able to click on the tel: link to initiate a call in Teams. Article for reference (or to feed to your own Copilot): Create a Hyperlink using SharePoint Calculated Column

Copilot suggested some modifications, so I'm not using a calculated column, but instead just a single line of text column with the phone extension. Then this JSON formatting:

{
  "$schema": "https://developer.microsoft.com/json-schemas/sp/v2/column-formatting.schema.json",
  "elmType": "a",
  "style": {
    "text-decoration": "none"
  },
  "txtContent": "='📞 Call ' + [$Title]",
  "attributes": {
    "href": "='tel:' + [$Extension]"
  }
}

Here's what it looks like in the list view, with the column formatting panel visible. 

You can then add it as a webpart to a page if you want.