Hello,

I’m the Developer Support Engineer assigned to you case.

I understand you’re having some concerns regarding the envelope usage and fees. The account that owns the access token and is making the request will be responsible for the envelope fees. The app creator (who owns the integration key) is not the one that pays for the envelopes; instead, the fees are charged to the account that sends the envelope, which is typically the account making the API request.

Please let me know if this answers your question.

Best,

Dev/API Team

​@Rafay.Khan 
Thank you very much for responding to me .
I have 1 more question. I am currently using a production account that has already ended its free trial, but I am still able to call the API and create envelopes with that account. My question is, why can I still call the API and create envelopes after the free trial has ended? 
I have thoroughly checked and am certain that the envelopes and API calls are made using the account_id of the account that has already ended its free trial

Oh, it seems like I can create up to 10 envelopes, right?