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The invoice will be deleted and all work logs will be in status "not charged" again.
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Implications of Deleting Issues or Work Logs in JIRA
Deleting Issues
If you delete an issue in JIRA, all work logs are deleted in JIRA, too. ictime does not change this JIRA behaviour. In fact, additional information for a work log from the ictime database is not deleted, but no longer accessible, as the work log is the base entity where all additional ictime information points to.
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When creating on invoice in ictime, we are saving some work log information in a completely separate database table. That means that summary and details for an invoice do never change, as they are taken from this table and we are not relying on JIRA work logs any longer. That means that deleting issues does not have any implications for existing invoices.
Deleting Work Logs
In general, it is not possible to delete work logs that have been invoiced. However, if somehow you reach to delete a work log that had been invoiced, there will be no impact on existing invoices, as data is taken from a different place, like described above.
Revoking an Invoice
If you "undo" an invoice, status of all work logs is once again set to "not charged". However, if work logs had been deleted (or issues with work logs had been deleted), they will be finally lost.