The WHMCS 9.1 Beta is now available for testing on staging environments.

Whether you're testing your own integrations and templates, running it on staging to see how it affects your day-to-day work, or just want to help us catch issues before general availability, here's what's changed. Please don't run this build in production. Get it on the WHMCS 9.1 Beta landing page.

WHMCS 9.1 Beta includes the following new functionality and enhancements:
WHMCS 9.1 adds a configurable Invoice Immutability setting and expands credit and debit note management throughout the Admin Area and Client Area, including a new sortable Balance column on invoices. Try issuing a note and switching immutability modes in staging.
If your installation isn't currently linked to a WHMCS Marketplace account, 9.1 now attempts to create one automatically during the upgrade, with a starter credit applied. After updating in staging, confirm the account connected correctly and check the catalog in your admin.
WHMCS can now apply maintenance releases automatically on a schedule you set, with each update backed up first and restored automatically if it fails. Set a schedule in staging and check the new Update History table after a run.
WHMCS 9.1 includes an optional preview of Iris, a redesigned navigation for the Admin Area. It's a preview, not the default template. Switch to it at Account > My Account and go through your usual admin tasks, then let us know what works and what doesn't.
WHMCS 9.1 adds a minimum password length and a password reuse limit for admins and clients, both configurable at Configuration > System Settings > General Settings > Security. Test a password against the new minimums in staging.
WHMCS 9.1 adds a migration path from the Stripe, Stripe ACH, and Stripe SEPA modules to Stripe Dynamic Payments without requiring clients to re enroll, plus support for redirect payment methods such as PayPal, Amazon Pay, iDEAL, Bancontact, and BLIK. Run the migration and test a redirect payment end to end in staging.
WHMCS 9.1 adds support for PHP 8.4, alongside continued support for PHP 8.2, and requires a new ionCube Loader version, 15.0.0. Upgrade ionCube Loader before updating to 9.1, and update to 9.1 before moving to PHP 8.4. Check compatibility at Utilities > System > PHP Version Compatibility.
The REST API v2 now covers a complete checkout path, taking a cart from creation through payment and provisioning, paying an existing invoice, and managing stored payment methods. Stripe Dynamic Payments, PayPal Payments, and PayPal Card Payments support redirect free payments server side. Run a cart through to checkout using the new endpoints in staging.
Beta builds are intended for testing, not production use. When WHMCS 9.1 reaches general availability, beta installations will update through the normal update process at Utilities > Update WHMCS. We'll publish full upgrade guidance alongside the GA release.
Found a bug, hit something confusing, or have thoughts on any of the above? Use the feedback form on the beta landing page, or drop it directly in the community thread for this release. Every response gets reviewed.