E-Invoice Generator

How to Use the Flow-Invoice E-Invoice Generator

1. Input Supplier Information: Enter your registered business name, 15-character GSTIN, address, state, and 6-digit PIN code. The state code automatically populates from the first two digits of your GSTIN.
2. Enter Recipient Details: Provide the buyer's legal business name, valid GSTIN, shipping address, and PIN code.
3. Specify Invoice Specifications: Enter your unique document serial number (up to 16 alphanumeric characters), issuance date, supply type (such as standard B2B or SEZ), and the 2-digit Place of Supply (POS) state code.
4. Add Line Items: Enter each item description, corresponding HSN/SAC code, quantity, measurement unit (NOS, KGS, PCS, etc.), unit price, discount, and select the statutory GST slab (0%, 5%, 12%, 18%, 28%).
5. Automatic Tax Logic: The generator dynamically compares your Supplier State Code with the Place of Supply (POS). If they match, it calculates CGST + SGST (50% split each). If they differ, it applies IGST (integrated tax).
6. Preview & Export: Click Live Preview to review the formatted tax invoice, Print / Download PDF for paper or digital distribution, or Export as E-Invoice JSON to get schema-compliant payload ready for the IRP.

What is an E-Invoice?

An e-invoice is not an invoice created by the tax department. Rather, it is a standard business-to-business invoice generated using your accounting or utility software that has been validated and authenticated by the central Invoice Registration Portal (IRP), which generates an official Invoice Reference Number (IRN) and a signed QR code.

Important Invoice Fields Explained

• Supplier & Buyer GSTIN: The 15-digit Goods and Services Tax Identification Number. The first 2 digits represent the state code, followed by 10 characters representing the entity's PAN, 1 entity code, 'Z' by default, and a checksum character.
• HSN / SAC Code: Harmonized System of Nomenclature (for goods) or Service Accounting Code (for services). Mandatory under GST rules (minimum 4 digits for turnover up to ₹5 Cr, 6 digits for turnover exceeding ₹5 Cr).
• Place of Supply (POS): The 2-digit state code where goods or services are delivered. Crucial for determining whether tax is intra-state (CGST+SGST) or inter-state (IGST).
• Supply Type: Defines the nature of transaction, e.g., standard B2B, supplies to Special Economic Zones (SEZWP / SEZWOP), or Export supplies (EXPWP / EXPWOP).

GST Calculation Rules in E-Invoicing

Tax computation in Indian GST follows strict mathematical rounding and territorial rules:

• Taxable Value: (Quantity × Unit Price) - Discount
• Intra-State Supplies (Supplier State = POS): CGST = Taxable Value × (GST Rate ÷ 2); SGST = Taxable Value × (GST Rate ÷ 2).
• Inter-State Supplies (Supplier State ≠ POS): IGST = Taxable Value × GST Rate.
• Round Off: The final invoice value is rounded off to the nearest rupee, with the difference captured in the Round Off line item.

Common Mistakes to Avoid

• Invalid Invoice Number Format: Invoice numbers cannot exceed 16 characters and may only include alphanumeric characters and symbols - (hyphen) and / (slash). Special characters like spaces or underscores are not permitted.
• Mismatch Between POS and State Code: In an intra-state transaction, setting the POS different from the seller's state causes tax calculation failures on the IRP.
• Incorrect HSN Length: Submitting 2-digit HSN codes when your turnover legally mandates 4 or 6 digits will result in schema rejection by the IRP.

Frequently Asked Questions