---
url: /gst-manager-whmcs/installation.md
description: >-
  Install GST Manager in WHMCS — upload the module, activate it under Addon
  Modules, enter your license, then run the guided Setup Wizard.
---

# Installation

Deploy GST Manager from initial upload to GST-compliant invoicing in five steps.

**Prerequisites:** Server meeting [Requirements](/gst-manager-whmcs/requirements), **Full Administrator** account, and a valid license key.

## 1. Upload the module

Upload the module package to your WHMCS server:

* Extract the release archive.
* Copy the `modules/addons/gst_manager/` directory into your WHMCS root `modules/addons/` directory.

## 2. Activate the addon

Navigate to **Setup → Addon Modules → GST Manager → Activate**.

![The GST Manager row on the Addon Modules page with the Activate button](/gst-manager-whmcs/img/gst-installation-activate.png)
*Setup → Addon Modules → GST Manager → Activate*

Activation initializes core components:

* **Database tables:** Creates `mod_gst_*` schema tables.
* **Tax rules:** Seeds baseline **IGST 18%** and **CGST 9% + SGST 9%** rules.
* **Integrity baseline:** Computes the initial HMAC-SHA256 file signature baseline.

**Role Permissions:** Under **Access Control**, grant **Full Administrator** permissions to ensure addon menus display properly. See [Why Full Administrator access](/gst-manager-whmcs/requirements#why-full-administrator-access).

::: danger If activation fails
WHMCS shows *"Activation failed. Check activity log for details."* Open **Utilities → Logs → Activity Log** for the reason — most often a missing or outdated ionCube Loader. See [Requirements](/gst-manager-whmcs/requirements).
:::

## 3. Enter your license

Navigate to **Addons → GST Manager → Global Settings → License**:

* Enter your license key in the **License Key** field.
* Click **Save Changes** to activate.
* An active license is required for client-area bank display and update management. See [Licensing](/gst-manager-whmcs/licensing).

## 4. Run the Setup Wizard

Opening **Addons → GST Manager** launches the **Setup Wizard** automatically:

* **Guided flow:** Steps through licensing, WHMCS settings, tax rules, business identity, SAC codes, bank details, and template deployment.
* **Mandatory input:** Step 3 (**GSTIN & Tax Rules**) is required; other steps can be skipped and configured later.
* See [the Setup Wizard](/gst-manager-whmcs/features/setup-wizard) for step-by-step guidance.

## 5. Verify

Generate a test invoice to verify:

* **Tax calculation:** Verify CGST/SGST (intra-state) or IGST (inter-state) line items.
* **Header & Footer:** Check that company **GSTIN**, PAN, and contact details display accurately.
* **Line item codes:** Confirm SAC and Purpose codes appear on relevant line items.

## Next steps

* [Setup Wizard](/gst-manager-whmcs/features/setup-wizard) — the 7 guided steps in detail
* [Configuration](/gst-manager-whmcs/configuration) — GSTIN, tax rules and company identity
* [Licensing](/gst-manager-whmcs/licensing) — key types and what an active license unlocks