Upgrading PHP on a WooCommerce store without a checkout outage
PHP versions have a fixed support life, and hosts eventually move everyone forward. Newer PHP is faster and safer — and it removes or tightens behaviour that old plugins relied on, which can turn into a fatal error in the middle of a checkout.
Know your deadline
Check which PHP version you run and when it stops receiving security fixes on php.net’s supported versions page. Check the WooCommerce server requirements and your host’s schedule for retiring versions.
Plan the upgrade yourself rather than waiting for the host to do it for you on a date you did not pick.
Test on staging
Switch staging to the new version, enable WordPress debug logging and walk through the whole store and a full checkout with every payment method. Deprecation warnings today are fatal errors in the next version.
Old, abandoned plugins are the usual problem. Update or replace them — the routine in updating WooCommerce plugins safely applies.
Switching production
Switch at a quiet hour with a way back: most hosts let you change the PHP version instantly. Place a test order right after and watch the error log.
Keep a scheduled checkout check running through the change. A fatal error on the payment step shows up in minutes, with the console and network evidence of what failed. Related: the HPOS migration and order emails that do not arrive.
Check your own store now with the free WooCommerce checkout checker: it walks the checkout in a real browser and shows the step where it stops.
Common questions
Which PHP version does WooCommerce need?
Check the current requirement on WooCommerce.com; use a PHP version that is still supported with security fixes.
What breaks when upgrading PHP?
Old plugins and themes using removed functions, which show as fatal errors, often only on checkout or in payment callbacks.
How do I upgrade PHP safely?
Switch PHP on a staging copy first, enable debug logging, place orders with every payment method, then switch production at a quiet hour.