Can we purchase monthly subscription?

Can we only pay for the months that we are using the tool? We would only use it from August through May

Yes, you can go for the Monthly subscription and you may upgrade your account for those months only.

To upgrade the account please refer to this guide:

https://www.jotform.com/help/331-How-to-Upgrade-My-Account

To cancel the subscription and downgrade to free refer to this guide:

https://www.jotform.com/help/341-How-to-Cancel-a-Subscription-and-Downgrade-Back-to-Free

Let us know if you have further questions.

Thanks.