Can a customer reopen a ticket?

Hi 水谷  yes, if an end user comments on a ticket with a status set to Pending, Solved, or On-hold, the ticket status is changed back to Open. 

The only time when the end user is unable to reopen the ticket is if the status is already “Closed”, but end users can create a follow-up request that references a closed ticket. 

You may find more info here: System Ticket Rules

Hope this helps!

Dear Audrey,

Thank you for the quick answer. 

Your answer is exactly what I wanted to know. 

I will also check the site you taught. 

Thank you.

Best Regard.

You're welcome! We're happy to help!