As more people turn to mobile devices to browse the web, one really useful way of catching the all important website lead, and more importantly making your users life easier, is by using tel: links to allow visitors to click a phone number on the site and have the browser auto populate the phones dialler ready to call.
<a href="tel:+441611234567" title="Call us today">0161 123 4567</a>
The big issue with implementing tel: links is that they are not supported by desktop browsers without plug-ins such as FoxtoPhone, if your a Firefox user with an Android device I highly recommend you install.
This lack of support results in a LOT of 404s generated by both human visitors and bots that follow the links. Yes you can style tel links to make human visitor less likely to click them, but people still do and there isn’t much you can do about bots and they are the ones that spam your logs with 404s.
the solution I have found is to pop a .htaccess rewrite to catch those devices that don’t support tel links and redirect them to the contact page.
RewriteRule tel\:\+([0-9]) /contact-me [R=301,L]