can user without jira access create and comment on service desk tickets?

[Bart Woznicki]

Does logging in to service desk create an account with JIRA access for each user creating tickets in service desk ?

[Phill Fox]

It is worth reviewing this page https://confluence.atlassian.com/servicedeskcloud/managing-access-to-your-service-desk-732528940.html if you have not already done so as it describes the different ways of managing access.

Essentially a user who only creates tickets in service desk does not get setup as a JIRA user but they will only have access to the service desk view of the ticket.  In this way you have unlimited Service Desk users regardless of your JIRA licence.