Each subscription plan is setup with recurring payments, so you will never run out of credits. When you run out of credits we will bill your account again and renew your credits with the same plan that you previously registered with. The auto-renewal feature can be turned off in your account settings, if you don't want it to bill you again when your credits run out.
To change your subsription plan, simply purchase a new one, your additional credits will be added to your credit total and any subsequent recurring purchases will use the new plan.
No. Your credits will not begin counting down until your demo period has expired. You essentially get a free 2 weeks of API access before your credits will start being used. If your demo period ends without having any credits in your account, you will loose access to the Airport codes API.
If you leave the default of recurring billing turned on in your account, you should never run out of credits. Your credit card will continually be billed when you run out of credits.
We also provide up-to-the-minute statistics in your account so you can monitor the requests made for your account and keep an eye on your Air-port-codes credits.
Air-Port-Codes