1. Read the target release notes and verify PHP, ionCube, database, theme and module compatibility.
2. Test the release in an isolated staging environment with the integrations your business uses.
3. Back up both the database and application files, including private storage and configuration.
4. Open Utilities > Update WHMCS, review the selected update channel and check for updates.
5. Resolve updater requirements, including temporary storage, memory, execution time and file access.
6. Set the maintenance message and begin the update through the displayed confirmation workflow.

The updater has requirements beyond ordinary page loading. A site can appear healthy while lacking sufficient temporary disk space or the PHP configuration needed to download and extract the release. Correct the specific requirement rather than broadly disabling server protections.

An update may not appear if the current PHP environment is incompatible with the target. Verify the release's supported combination before changing PHP. The newest release channel is not necessarily the right production choice.

Confirm the installed version and inspect System Health. Test administrator and customer access, product pages, a controlled order, ticket submission, payment processing and the next relevant cron run. Review any third-party addon that affects invoice or service lifecycle events.

Check custom templates against the release's template changes. Replacing the core application does not automatically update a separately maintained theme.

Preserve the error and determine whether downloading, file replacement or database migration failed. Do not repeatedly start another update while the current state is uncertain. Follow the vendor's documented recovery for that failure or restore the coordinated file and database backup.

Keep the backup until critical workflows have passed. Record the release, time, validation and any follow-up work so the next administrator can distinguish a completed upgrade from a partially recovered attempt.

• Check WHMCS requirements before installing or updating
• Build a WHMCS staging copy without sending live charges or emails
• Update WHMCS manually when the automatic updater is unavailable
• Maintain a custom WHMCS theme across upgrades

• WHMCS: updating WHMCS
• WHMCS 9.0 release notes