First of all you have to register as a customer by giving simple personal details.
No, Email ID must be unique for each and every User.
There is no deadline, but at least 2 hours before, outside of peak seasons, holidays, weekends. (Applies only to ordinary taxi trips). Day trips, sightseeing, business, VIP, Minibus, tour bus, in sufficient time. As these are often booked months and weeks in advance.
Cancellation 24 hours before pickup will result in a refund of the amount paid to your account, minus NOK 100 in transfer fees. (Between 24 hours - 12 hours, 30% will be deducted from the amount paid before the excess is returned.) Less than 12 - 9 hours, 50% will be deducted. Less than 9 hours, no refund.