The purpose of visit locking is to prevent accidental changes to visits which would result in unintentional inconsistencies between the visit data and billing and/or payroll.
Visits are locked as soon as they have been included in an invoice or payroll run. Additionally, visits can no longer be deleted once they have been locked.
Locked visits are distinguishable by their lock icon in visit lists:
and in the visit dialogue:
Only users with the ACL Edit Locked Visits can make changes to locked visits.
When editing the visit, a user with the ACL will need to override a warning dialogue:
For premiums, the dialogue looks a bit different but contains the same message:
If the user overrides the warning, the change to the visit is saved.
Any invoices or payroll runs which involve the visit can be viewed in the visit's accounting tab:
Finally, note that visits cannot be deleted once they have been included in payroll or an invoice, to prevent data errors.
Visits can still be cancelled for a non-billable or non-payable reason, with the appropriate permissions.