GSTR-1 is a key return under the Goods and Services Tax (GST) system in India. It’s a monthly or quarterly return that businesses registered under GST need to file to report details of their outward supplies of goods or services.

     Here are the key points about GSTR-1

1.Reporting Outward Supplies: GSTR-1 contains details of all outward supplies made by the taxpayer during a particular tax period. These supplies include both
business-to-business (B2B) transactions and business-to-consumer (B2C) transactions. 

It covers all types of supplies such as sales, exports, and supplies to SEZs (Special Economic Zones).

2. Invoice-wise Details: Taxpayers are required to provide invoice-wise details of their outward supplies in GSTR-1. This includes information such as invoice number, invoice date, customer details, taxable value, and applicable GST rates.

3. Other Details: Apart from invoice-wise details, GSTR-1 also includes information on debit and credit notes issued during the tax period, amendments to invoices for previous periods, and consolidated details for supplies attracting reverse charge mechanism. 

4. Due Date: The due date for filing GSTR-1 varies depending on the turnover of the taxpayer. For businesses with a turnover exceeding a certain threshold, it’s typically the 11th of the following month. For taxpayers with turnover up to a certain limit, it may be quarterly.

5. Importance: GSTR-1 is crucial for reconciliation and input tax credit (ITC) claims by the recipients of goods or services. It also helps tax authorities verify the tax liability of the taxpayer and ensure compliance with GST regulations. 

6. Penalties for Non  -Compliance: Failure to file GSTR-1 or filing it late can attract penalties and interest charges under GST laws.

Overall, GSTR-1 is an essential component of the GST compliance framework in India, providing transparency and accountability in the reporting of outward supplies by registered taxpayers.