<h1>Section 16(4) CGST Act: ITC Claims for FY 2020-21 Must Be Filed by October 2021 GSTR-3B Deadline.</h1> Under Section 16(4) of the CGST Act, 2017, taxpayers cannot claim input tax credit (ITC) for goods or services supplied in the financial year 2020-21 after the due date for filing the GSTR-3B return for September 2021. This deadline is 20th October 2021 for monthly filers and 22nd or 24th October 2021 based on the taxpayer's registration location. Records submitted after this deadline will not be reflected as available ITC in GSTR-2B or GSTR-9. Taxpayers are advised to ensure timely reporting to avoid non-compliance and potential legal action.