Please send an email to Validation [dot] Support [at] easa [dot] europa [dot] eu. We will investigate and confirm, for which category you need to apply.
“Forwarding Letter only” (Category “Small”): For third countries that have neither a Bilateral Agreement nor a Working Arrangement with EASA in place.
“Technical Support” (Categories “Medium” and “Large”): For third countries that have a Bilateral Agreement and/or Working Arrangement with EASA in place, i.e. USA, Canada, Brazil, China, Japan, and Russia.