Hi @martina13503,
Welcome to the Klaviyo Community! Would you mind going to the profiles tab and checking to see how many active profiles you have? Klaviyo billing is based on active profile count, and an active profile is any profile that has provided their email, and hasn’t specifically unsubscribed or been suppressed.
Because of this, some profile that haven’t explicitly subscribed would be considered active profiles, as long as they never unsubscribed either. A classic example of an active profile is somebody who provided their email at checkout, but never actually subscribed. Since Klaviyo does technically allow you to email profiles such as this, they’re considered active profiles.
If you’d like to reduce your active profile count in order to ensure that only your subscribers count as active profiles, you can make a segment with the definition “Person can receive email marketing because person subscribed”, and then suppress that segment. After doing this, these profiles will be unable to be emailed, and you also won’t be charged for them. Let me know if this makes sense, or if I can answer any additional questions.