I'm a Sitecore certified developer and am moving company soon. Does anyone know of a way I can inform Sitecore so that I can continue to log in to the support portal and create support tickets for my new company (partner)
You can contact Sitecore support to update email address. So just email address changes to login to SPN. All your achievements and progress will be there. Sitecore support team will merge account, so nothing will be lost. You can use below links to contact sitecore support team.
Fill the form and wait for their reply.