Requirements

Confirm your server and Zoho account are ready before you install. Most WHMCS hosts already meet the software requirements.

Server and software

Requirement	Details
PHP	8.2 or newer (runs on 8.2, 8.3, 8.4 and 8.5)
WHMCS	8.13 or newer, or 9.x
ionCube Loader	13.0.2 or newer (see below)
PHP extensions	curl, openssl, json, and mbstring enabled
SSL certificate	Required for the webhook endpoint
Zoho account	A Zoho account with Payments API access
License	An active Zoho Payments license

Required PHP extensions:

• curl and openssl: Handle secure outbound HTTPS requests to Zoho.
• json: Encodes and decodes API payloads.
• mbstring: Manages multi-byte string formatting.

The ionCube Loader

Zoho Payments for WHMCS is ionCube-encoded and requires the ionCube Loader PHP extension:

• Environment support: Because WHMCS requires ionCube, compliant hosting environments already have it enabled.
• Minimum version: Requires ionCube Loader 13.0.2 or newer (compatible with PHP 8.2+, 8.3+, and 8.4+).
• Single build: One encoded package operates across all supported PHP and loader versions.

ionCube Loader required

If ionCube Loader is missing or older than 13.0.2, the gateway cannot execute. Enable ionCube Loader 13.0.2+ for your PHP version before activating the module.

Why a Zoho account with Payments API access

The gateway interacts directly with Zoho APIs to render widgets and verify transactions:

• Payments API access: Required to generate payment sessions and query transaction statuses.
• OAuth credentials: Client ID, Client Secret, and Refresh Token configured via the Zoho OAuth setup guide.
• SSL certificate: Zoho delivers Payment Link webhook notifications exclusively to valid HTTPS endpoints.

Why a license

An active license enables payment processing:

• Active license: The gateway accepts new payments and verifies incoming transactions.
• Inactive license: New checkouts are suspended until a valid key is provided. See Licensing.

How to check

• PHP and extensions: In WHMCS, open Utilities → System → PHP Info to verify PHP version and loaded modules (curl, openssl, json, mbstring).
• ionCube Loader: Confirm the ionCube section in PHP Info displays version 13.0.2 or higher.
• SSL certificate: Verify that your WHMCS installation loads over a valid https:// connection.
• Zoho account: Ensure access to the Zoho Developer Console for your chosen data centre (India or US).

Related pages

• Installation — upload, activate, and configure
• Zoho OAuth setup — app, refresh token, and webhook
• Configuration — walk through every gateway field
• Licensing — Leased vs Lifetime and your key