noun
sign up; registration
Common loanword for creating an account or registering for a service, especially online.
新しいアプリにサインアップするのにメールアドレスが必要です。
You need an email address to sign up for the new app.
Variant with interpunct; less common in everyday use.
登録 is the native Japanese term for registration, used in broader contexts including official documents and memberships. サインアップ is more casual and specifically refers to the act of signing up, often online.
Loanword from English 'sign up', adopted into Japanese with the same meaning.