<a href="tel:+44-785-7895">+44-785-7895</a>
Area code with dashes, 1 and + sign
<a href="tel:+1-555-555-1212">555-555-1212</a>
Area code with no dashes, 1 and + sign
<a href="tel:+15555551212">555-555-1212</a>
<a href="tel:8895959595">call this number 889-5959595</a>