If I leave mid-month, do I pay half?

No, and here's exactly how it works: the current month stays due in full — it's month-to-month, not prorated by the minute — and the service stays active until the last paid day. Conditional forwarding, however, can be disabled from the moment you ask: your line becomes normal again immediately, even if the account runs to the 30th. Cancellation is confirmed in the dashboard, with written validation within 24 h and no exit fees. The following month is never billed after confirmation — no sneaky auto-renewal.