In Radiojar, you're charged for the first month as soon as you create your radio station.
The billing cycle, however, does not start immediately. It starts after you have activated your station. An active radio station can immediately start broadcasting. Before you activate your station you can take your time to set up your shows, invite DJs and set up your library before starting the billing cycle. This way you won't waste any bandwidth/storage before your station starts broadcasting.
When you activate your station, a monthly billing cycle begins. On the same date next month, you will be charged the price of your plan for the month ahead. If you've consumed any resources above your plan's limits during the past month, those will be charged as well. This continues as long as your radio station is active and broadcasting. You can see your station's plan usage, invoices & balance, choose to change your plan or even deactivate your station from the settings area.