Do I need a CV on file before I can apply?

No. Applying takes an account and nothing more. On a job page, press Apply and either continue with Google or enter an email address and password — that one screen creates your account and sends the application together.

The employer sees it straight away: your interest in the role, the email address to reach you on, and — if you signed up with Google — your name. Their copy of the application shows that your CV has not arrived yet, so they know to expect it rather than wondering what is missing.

The confirmation screen then offers you one thing: Add my CV now. If you have the file to hand, it uploads there and then without leaving the page. If you do not, choose I'll do it later and add it whenever you like from the Profile tab in your account.

Adding your CV is still worth doing, and soon: employers reply faster when they can read your experience instead of an email address alone, and your CV is what fills in your name, specialties and background across the site. When you add it, it does not only go out with future applications — it is added to the applications you have already sent, and the employers still waiting on it are told it has arrived.