If you happen to install a new Debian server using stretch and want to have multiple php versions, you might have seen https://deb.sury.org/ I assume a fresh installation, else there might be the need to update all your vhosts similar Howto: https://www.howtoforge.com/tutorial...fig-3-from-debian-packages-on-debian-8-and-9/ worth reading https://packages.sury.org/php/README.txt Get surys repo added to your system. Install the versions you want and also the modules you need. But make sure you got the -fpm packages. Code: apt-get install php5.6-fpm php7.1-fpm php7.2-fpm php 7.0-fpm .... Make sure there is max php7.1-fpm enabled as default php parser in your conf-enabled. At least if you use this to run your webmail/phpmyadmin webapplications. Code: a2disconf php-7.2-fpm a2disconf php7.0-fpm ... a2enconf php7.1-fpm This config kind of replaces mod_php behaviour, if you did not get rid of it yet, disable it and use apache mpm_worker ; or if you are on debian 10+ you can probably use mpm_event, don't use mpm_event on stretch if you haven't patched it manually! However this particular a2dis/en block following is optional Code: a2dismod mod_php... a2dismod mpm_prefork a2dismod mpm_event a2enmod mpm_worker If you did this however, also check https://www.howtoforge.com/communit...-enigma-munin-phpmyadmin-using-php-fpm.77489/ https://www.howtoforge.com/communit...l-port-8080-with-lets-encrypt-free-ssl.75554/ https://www.howtoforge.com/community/threads/pfs-letsencrypt-for-postfix-dovecot-pureftpd.77499/ // end of optional Check the example www*.txt files on this thread, you need one default process running for all your php-fpm versions! copy them to your /etc/php/x.y/pool.d/www.conf In ISPConfig go to System>Serer configuration>Web and change accordingly to the picture. edit: I didn't bother with the apache php.ini setting, change it, too if you need it Making PHP 7.2 default, since your default $php -v command is linked to php 7.2, explain to your customers you provide different versions and they might need to adjust their cronjobs or cgi files using /usr/bin/php5.6 ... /usr/bin/php7.2 Use the following values accordingly to add your additional PHP versions as fpm - because who wants fastcgi ( ahh you can figure that out ). if I didn't miss anything that should be it.