Use a private test installation with appropriate licensing and isolated payment, registrar and server connections. Where a provider offers a sandbox, use its documented test credentials. Do not submit a real domain registration or charge a real customer merely to confirm that a button works.

Choose representative products: a basic hosting plan, a plan with configurable options, an addon, a domain and a product requiring manual review. Record expected first charges, renewal charges, due dates and remote resources before running them.

1. Open the public order link in a fresh session. Confirm the product group, billing cycle, option labels, tax display and amount payable.
2. Test required fields and an ineligible coupon as well as the successful path. Error messages should explain what the customer must correct.
3. Complete checkout with the provider's test payment flow. Check the invoice transaction and gateway result.
4. Inspect the order review status and the service status separately. Confirm that provisioning occurs at the configured trigger.
5. Check the remote account, package, domain and resource limits. Test the expected client-area access.
6. Review the welcome and invoice messages in the controlled mail destination. Verify links and product-specific instructions.

Test a declined or incomplete payment and confirm that the service is handled according to policy. Reproduce a controlled provisioning error to ensure that staff can find the queue entry and recover it. Test cancellation and refunds separately, with no production account attached.

Inspect the stored recurring amount and next billing dates. A discounted first payment should not accidentally become an undocumented permanent price. Record the results and clean up test resources deliberately, retaining enough evidence to repeat the test after an upgrade or catalogue change.

• Build a WHMCS staging copy without sending live charges or emails
• Choose and test a WHMCS order form for a product group
• Activate and test a WHMCS payment gateway
• Investigate a paid WHMCS order that did not create hosting

• WHMCS: set up a test environment
• WHMCS payment gateways
• WHMCS: automatically provision services
• WHMCS billing logic