Keep a clean starting version
Save a version of the agreed service package and export a backup. Start the next invoice by duplicating that record, so the earlier invoice remains available.
Update every time-sensitive field
Check the invoice number, service period, issue date, due date, current rates and customer reference. A duplicated document can contain stale dates or an old purchase order even when its total looks correct.
Check changes and payments
Remove work no longer included and add only approved extras. Confirm whether a deposit or payment belongs to this period before entering it. A previous month’s payment must not reduce a new month’s bill.
Keep a sending record
Export the reviewed PDF, send it through your own email service and record when you sent it. The manual Sent status is a reminder for you, not proof of delivery or an automatic reminder system.