Authorisation for GST Practitioner governs specified taxpayer acts and affects input tax credit matching and liability adjustments. Form GST PCT-05 authorises or withdraws a Goods and Services Tax Practitioner to perform specified electronic compliance activities for a taxpayer; it requires the taxpayer to select the exact activities to be authorised, include the practitioner's name and enrolment, attach the practitioner's written consent, and execute signature and identification details. The accompanying schedule summarizes return matching outcomes-accepted input tax credits, mismatches and duplicates that increase liability immediately or in subsequent returns-and notes prior notifications affecting items and procedures.