---
url: /gst-manager-whmcs/requirements.md
description: >-
  What your server and WHMCS install need before you run GST Manager — PHP,
  WHMCS, the ionCube Loader, PHP extensions, an active license and an Indian
  WHMCS store, with how to check each one.
---

# Requirements

Before you install GST Manager, take a minute to confirm your server meets the requirements
below. Most WHMCS hosts already do — the **ionCube Loader** is the one worth checking first,
because GST Manager will not run without it.

## 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`, `zip`, `mbstring` |
| **License** | An active GST Manager license |
| **Store** | A WHMCS store selling to Indian customers |

## The ionCube Loader

GST Manager ships as an ionCube-encoded build, so your server needs the **ionCube Loader** — a
small, standard PHP extension that runs protected commercial software. It is the *same* loader
WHMCS itself requires, so a server already running WHMCS almost always has it and you rarely need
to install anything new.

You need **ionCube Loader 13.0.2 or newer**. The exact version tracks your PHP version — WHMCS on
PHP 8.2 uses 13.0.2, PHP 8.3 uses 14.4.0, and newer 15.x loaders work too. One encoded build runs
on every supported PHP and loader version, so there is nothing to match up.

::: danger GST Manager will not run without ionCube
If the loader is missing or too old, GST Manager's encoded pages can't run — they show
`ionCube Loader required. Contact support@relyweb.co`. Ask your host to enable **ionCube Loader
13.0.2 or newer** for your PHP version, then reload.
:::

## Why an Indian store

GST is India's **Goods and Services Tax**. GST Manager exists to make your WHMCS invoicing
compliant with it — automatic IGST/CGST/SGST tax rules, a GST invoice format carrying your
**GSTIN** (your 15-character GST registration number), and the CSV reports you file with. If you
don't sell to Indian customers, GST doesn't apply and this module isn't for you.

## Why a license

GST Manager requires an active license — the client-area invoice bank-details feature is
licence-gated. You enter your key after activation — see
[Installation](/gst-manager-whmcs/installation) — and manage it later under
**Addons → GST Manager → Settings → License**. See [Licensing](/gst-manager-whmcs/licensing) for
how the license types work.

## How to check

You don't need to guess at any of this:

* **PHP version and extensions** — open **Utilities → System → PHP Info** in the WHMCS admin, or
  ask your host. Confirm PHP 8.2+ and that `curl`, `openssl`, `json`, `zip` and `mbstring` are
  loaded.
* **ionCube Loader** — the same **PHP Info** page lists the ionCube Loader and its version if it
  is installed. If you can't find it, it isn't enabled.
* **WHMCS version** — shown in the WHMCS admin footer, and under **Help → System Health Status**.

::: tip Ready to install?
Once your server checks out, head to [Installation](/gst-manager-whmcs/installation) to upload,
activate and license GST Manager.
:::