Insert tag in snippet?

I’m building a site using separate snippets for both the header and footer, I need to show the phone number in both the header and footer and throughout the home page and on the contact page.

At the moment I have stored the phone number as a field on the home page content txt file (telephone) so the user can update this in the home blueprint.

I have it placed a few times through the home page using:

<?php
    $home = page('home');
?>
<?= $home->telephone() ?>

But the problem is this doesn’t work in the header and footer snippets and says $home is undefined?

What is the best way/place to store this and show it multiple times throughout the site?

Thanks.

I’d store such information in the $site object (site.txt), which is supposed to be the place for all site wide information, rather than the home page.

$site is automatically available in templates and snippets-