How can I change the security level of a custom field after a value has been entered in the field?

Reinout van Noort

We are adding new custom fields to our Jira instance.

These custom fields need to be viewable by our clients, but should not be editable except for certains users part of an existing group.

I do not see the custom fields in the project permissions, so please let me know how I can change the security level of a custom field?

Nic Brough -Adaptavist-

You do not.  Jira does not have field-level security.

There are a couple of apps that enable some form of field-level security, but plain Jira does not do it at all.  It only goes down to issue-level security.