The Registration Application form with various tabs is displayed. Note: You must have your Letter of Authorization notarized using the Certificate of Acknowledgement attached.A letter of authorisation for GST is an essential document regarding taxation and business operations. Authorisation Form:- For each Authorised Signatory mentioned in the application form, Authorisation or. In a firm, the person responsible for managing the GST proceedings has to often fill the forms themselves or pay a visit to the GST office. S.No. Subject, Date. The best time to lodge your return is from late July, when most of your information is prefilled into your tax return. The official website of the Food Safety and Standards Authority of India (FSSAI) for all food license-related work.