In most cases, yes. If you've ordered prints from theprintspace before or already set up an art store, you'll have a creativehub account, and that's the same account you use here — just sign in with the email address you registered with rather than creating a new one. Existing customers can log in and pick up where they left off, with previously uploaded files, saved addresses and payment details ready for quick re-ordering.
If you try to sign up and your email is already recognised, that's a sign you already have an account — in that case, log in instead (you can reset your password if you've forgotten it). You can also update the email your account is registered to from your account settings if needed.