No, you cannot change the document number of a CCN or CRN once it has been submitted. If you have entered the information incorrectly, you must cancel the incorrect document and then create the correct CCN and/or CRN and submit to the CBSA. Please see section 6.7 (Cancelling a Submitted Document) of the eManifest Portal user guide for more information. https://www.cbsa-asfc.gc.ca/prog/manif/portal-portail/guide-eng.html.