Need advice on how to code "Tap to call" button
 

Hi,

My current coding is:
<p align="center"><a href="tel:61560975">
<img border="0" src="images/tel.png" width="282" height="50" class="v6col"></a></p>

61560975 is a local number in NSW, so if someone calls from say Melbourne, it won't work.

The area code for NSW is 02
The country code for Australia is 0061

So the full string for the number is :0061261560975

Would the code on a mobile phone link then be:
tel:+61261560975

or if calling from within Australia:
tel:261560975

Bit confused about when to use the "+" sign

I've just been using "tel:61560975", and hoping no-one calls from outside NSW

Thanks in anticipation