If you've accidentally omitted GSTINs for your suppliers in previous GSTR 1 filings, don't worry. The recommended solution is to include these invoices in your current month's GSTR 1. You can then use the 'amend' option for B2C (Business to Consumer) in GSTR 1 to correct the details for the past periods.
12 March 2020
Due to mistake, GSTIN of many suppliers were not mentioned by me in previous months GSTR 1, which came to my knowledge only now. How can I rectify the mistake ?