You can add this via text tab or if you are using a builder within wordpress. To be honest I’m not a massive fan of the text tab option I add a button via the builder, I then make the button only visible on mobile & tablet. I think it’s daft to show a ‘tap to call’ button on desktop because the likelihood is that no one will tap on a desktop machine… it’s more for mobile. Once they tap the button on their mobile it will open the call screen on their mobile
Text Tab: <a href = “tel:01414391439”>Tap-To-Call</a>
Builder Button: “tel:01414391439”
Source: http://www.prasenjitsharan.com/quick-tip-use-html-5-to-create-tap-to-call-hyperlinks/
