signing authority in all documents

Sujit Kumar Das (75 Points)

12 August 2017  
Dear All
As per chapter of the Act & Rule all papers like invoice, dr note, cr note, receipt voucher, payment voucher, refund voucher, letter, permision, intimation etc are to be signed by authorised representative.
what procedure to be followed to make an employee as an authorised representative under gst act?
Anyone can help with the prov of section of the act.
Regards
Sujit Kumar Das
9433036600