---
url: /gst-manager-acellemail/guides/configure-gst.md
description: >-
  Walk through Setup → Company & Tax to enter your GSTIN, home state, default
  rate, tax label, SAC/Purpose codes and invoice numbering so every AcelleMail
  invoice is GST-compliant.
---

# Configure GST

Get GST Manager producing correct tax invoices by filling in **GST Manager → Setup → Company & Tax**.

**Prerequisites:** your **GSTIN** (15-character GST registration number) and **PAN** to hand.

![The Company & Tax setup screen](/gst-manager-acellemail/img/gst-configure-gst-company-tax.png)
*GST Manager → Setup → Company & Tax*

::: info Why this matters
Your home state and GSTIN drive the tax engine: **CGST + SGST** (sale inside your state) vs a single **IGST** line (sale to another state), and **B2B** (customer has a GSTIN) vs **B2C** (they don't).
:::

1. **Company info** — enter **Company name** and **Company GSTIN**. Shared with your AcelleMail admin contact (editing here updates it). Type the GSTIN carefully; it prints on every invoice — see [GSTIN validation](/gst-manager-acellemail/guides/gstin-validation).

2. **Address and home state** — fill **Address line 1/2**, **City**, **ZIP / PIN**, **Country**, then set **State** (your registered home state). State help: *"Used to decide CGST+SGST vs IGST. Matched against the Indian states registry."*

3. **Tax & GST** — set the **Default GST rate** (e.g. 18) and **Tax label** (*"Shown as the label of the consolidated tax line on PDFs (e.g. GST)."*; most sellers leave it as **GST**).

4. **SAC & Purpose code** — enter your **SAC code** (service accounting code) and **Purpose code** (RBI export-payment code). Both are *"Applied to every line item on every invoice."* See [GST classification](/gst-manager-acellemail/features/gst-classification).

5. **Invoice numbering** — set the **Invoice number format** and **Next invoice number**. The format uses a `sprintf` template:

   ```text
   %08d      → 00000001
   %d        → 1
   INV-%06d  → INV-000001
   ```

6. **Save** — click **Save changes**; you'll see *"Settings saved."*

7. **Verify** — download an invoice and confirm it carries your GSTIN, the correct tax split, and your numbering.

::: tip These two are core settings
The invoice number format and next number are **AcelleMail core settings**, shared with general settings — changing them here changes them everywhere. Set the next number to continue your existing sequence rather than reset it.
:::

Continue with your invoice logo, footer and bank details in [Invoice identity and bank details](/gst-manager-acellemail/guides/invoice-identity-and-bank).

## Related pages

* [GSTIN validation](/gst-manager-acellemail/guides/gstin-validation)
* [Invoice identity and bank details](/gst-manager-acellemail/guides/invoice-identity-and-bank)
* [GST classification](/gst-manager-acellemail/features/gst-classification)
* [Settings reference](/gst-manager-acellemail/settings)