PHP Upgrade

[Geppux]

VM 3.0.16 - J 3.5.1
When I open Akeeba to backup my site, I receive this warning:

You are using an obsolete PHP version

Your site is running on PHP 5.4.4-14+deb7u2 which has stopped receiving security updates since Giovedì, 03 Settembre 2015. Using this on a live site is dangerous: unpatched security issues can get your site hacked. Moreover, we can only guarantee support for obsolete versions of PHP after nine months since their end-of-life date. Therefore, support for your version of PHP may be dropped any time after Venerdì, 03 Giugno 2016. We strongly advise you to ask your host to upgrade your site to PHP 5.6 or later.

I would like to know what I risk upgrading to a newer version of PHP... the site could stop working?
I tried to install locally the site with a recent PHP version and it seems to work, but I would like to have your advise... thank you.

Giuseppe

[GJC Web Design]

I am running the majority of my sites on php7 -

be aware if your using VM encrypt for payment plugins etc to check the functionality carefully
http://forum.virtuemart.net/index.php?topic=133436.msg462716#msg462716
but generally imho J3.51/VM3.0.16+ are php7 ready

3rd party extensions you have to experiment

[Geppux]

Thank you GJC for the answer. Actually I use only Paypal payments so I don't think to have problems about it.
Giuseppe

[GJC Web Design]

I use only Paypal payments so I don't think to have problems about it

correct .. I have only seen it where vm encrypt is used to locally store cc numbers etc