Revocation of cancelled GST registrations: limited opportunity subject to furnishing outstanding returns and portal constraints. The circular clarifies that revocation of registration cancelled for non furnishing of returns is permitted only after all returns due up to the cancellation order are filed and dues paid; where cancellation is retrospective and portal constraints exist, the Rules allow an application for revocation provided all returns for the period from the effective cancellation date to the revocation date are filed within the prescribed period after revocation.