This tutorial explains how to generate an Amendment to Warrant certificate for an existing certificate, which may be staged or non-staged.
Note that when generating an Amendment to Warrant certificate for a staged project it is only possible to select the most recent certificate for the project to amend, although you can amend the stage description for all stages while generating the new certificate.
The tutorial includes information about how to generate an Amendment to Warrant certificate for a project for which more than one stage was created using the pre-October 2016 SER system.
Further information regarding managing post-certification design changes can be found in Guidance note 8 - Managing Post Certification Design.