Is the Apple iOS provisioning device limit cumulative?

Question

We are coming up to our iOS Developer Program renewal date and I want to make sure I fully understand how the device limit works so we maximise the number of test devices.

Am I right in thinking that the 100 device per year is on top of what we already have? Therefore, should we be aiming to add as many of the 100 devices before we renew to get the most out of the limit?

Does that mean that after two years of membership you can have up to 200 devices?

I found this in the Developer Support Center but it didn't really answer my question:

How many iOS devices can I register for testing and Ad Hoc distribution?

You are allowed to register up to 100 iOS devices for testing and Ad Hoc distribution per membership year. Please Note: Although you may remove a device from your account, it will continue to count against your 100 device limit.

How do I reset my list of iOS development devices in the iOS Provisioning Portal?

At the start of your new membership year, Team Agents or Admins can sign in to the iOS Provsioning Portal to remove listed devices and restore the available device count to 100 devices. Be sure to remove all devices you no longer use for development prior to adding any new devices.

Answer 1

You are allowed to register up to 100 iOS devices for testing and Ad Hoc distribution per membership year.

=> You always have a limit of 100 devices.

At the start of your new membership year, Team Agents or Admins can sign in to the iOS Provsioning Portal to remove listed devices and restore the available device count to 100 devices.

=> When you renew your membership, you have the opportunity to free some of the used slots by removing some or all of the previously registered devices.

Be sure to remove all devices you no longer use for development prior to adding any new devices.

=> once you add a new device, you can no longer free any used slot, and even if you remove a device, it will continue to count against the 100 limit.

Answer 2

The limit is not cumulative.

You get 100 "slots" for devices, and once per year, you can delete the devices you are no longer using for testing, and thus reset your count back to 0 for a 100 "new" devices.