Pre-filing draft offer document requires lead manager due diligence and public notice before progressing an IPO. Pre-filing permits an issuer to submit a draft offer document to the regulator and stock exchanges through lead manager(s) before an IPO; pre-filed drafts stay non-public. Lead manager(s) must provide agreement and due diligence certificates and an undertaking against marketing. The issuer must make limited public announcements. The regulator may issue observations within a prescribed period; the issuer and lead manager(s) must incorporate changes and file an updated draft red herring prospectus-I, host it for public comments, report comments, and subsequently file an updated draft red herring prospectus-II and the final offer document with required certifications and auditor confirmations.