There is no limit in the number of subscriptions you can create. However, you can only have as many active subscriptions as the number of subscriptions your team has purchased. Teams in the Free Plan can create up to 2 subscriptions, and they will have limited features.
In case you are in the Team Plan, you will always be able to create subscriptions if you have enabled the «Auto-increment total subscriptions» setting in the Team Administration Panel, and you will be billed for the corresponding amount.
A popup window will appear, in which you can modify the number of subscriptions of your team, and enable/disable the «Auto-increment total subscriptions» setting.
Once this setting is enabled, there will be no limit in the number of subscriptions you can create!