Under Indian GST law, a GST-compliant invoice must include specific details to ensure that it meets the legal requirements for input tax credit (ITC) and other compliance purposes. The mandatory details required in a GST-compliant invoice are as follows: Name, Address, and GSTIN of the Supplier: The name and address of the supplier, along with their GSTIN (Goods and Services Tax Identification Number), must be mentioned. Name, Address, and GSTIN of the Recipient: If the recipient is a registered taxpayer, their name, address, and GSTIN must be included. If the recipient is unregistered, the recipient's details must still be captured, but GSTIN is not required. Invoice Number: A unique invoice number, which should follow a sequential order (e.g., from 1 onwards), is mandatory for every invoice issued. Date of Issue: The date when the invoice is issued must be clearly mentioned. Description of Goods or Services: The invoice should contain a clear description of the goods or services supplied, including the quantity, unit of measurement, and value. HSN (Harmonized System of Nomenclature) Code: The HSN code for goods or SAC (Service Accounting Code) for services must be mentioned. This is required for transactions exceeding a specified turnover threshold. Quantity and Unit Price: The quantity of the goods or services provided, along with the unit price (excluding tax), must be clearly mentioned. Total Value of Goods or Services: The total value of the goods or services supplied (before GST) should be indicated. GST Rates: The applicable GST rate (CGST, SGST/UGST, or IGST) should be mentioned clearly for each item or service. This includes the rates for both central and state taxes, if applicable. GST Amount: The amount of GST (CGST, SGST/UGST, or IGST) applicable on the total value should be mentioned separately. Total Invoice Value: The total value of the invoice, which includes the value of goods/services and the GST amount, must be mentioned. Place of Supply: The place of supply (state) must be mentioned in cases of interstate supply. For intrastate supplies, it is not mandatory but recommended. Signature: The signature or digital signature of the supplier or authorized person must be included, especially in case of manual invoices. Payment Terms: If applicable, the terms of payment (e.g., due date, advance received, etc.) should be mentioned. Other Relevant Information: Any additional details like reverse charge applicability, export invoice details, etc., may be included depending on the nature of the transaction. For export invoices, additional information such as the mention of the export nature (export with or without payment of GST), shipping address, and relevant export code must be included. These details ensure that the invoice complies with GST laws and allows for seamless input tax credit claims and other compliance processes.