It is important to update them to a newer version. We would recommend updating to either:
- 7.2 supported until 30 November 2020
- 7.3 supported until 6 December 2021
As with any upgrade you will want to test your site on the new version before migrating. You may need to get your developers to update some code, check plugins and app versions for the new PHP supportability.
If you love a pie chart, Jordi Boggiano has provided this great overview of the PHP versions out there.
Upgrade from PHP 7.1 before the 1st December 2019.
Want a hand? Get in touch!