What "amending" means depends on where the invoice is in its lifecycle. While it's still a draft, nothing is locked: edit it freely, and the changes appear on the next print. Once it's issued, the document is immutable (that's what makes it a proper VAT record), and corrections go through a credit note instead.
Amending a draft
- Forgotten labour line or wrong price: fix it on the jobcard, then click Refresh on the draft to rebuild it from the jobcard (this discards any edits made directly on the draft)
- Line-item tweaks: edit the draft's line items directly on the invoice page
- Wrong VAT rate: toggle VAT on the affected job, then Refresh
- Not ready to bill after all: Delete draft removes it entirely
Amending an issued invoice
Click Amend on the invoice and give a reason (it's required, and stored against both documents). Pistonlog then:
- Issues a credit note cancelling the original invoice
- Creates a replacement draft, rebuilt fresh from the jobcard's current state
Fix whatever was wrong, then issue the replacement. Any payments already recorded stay attached to the original invoice. If you just want the invoice gone with no replacement, use Cancel, which issues the credit note only.
If a customer has already paid and you need to refund part of it, the refund itself happens outside Pistonlog (cash back, bank transfer). Amend or cancel the invoice so the paperwork matches, and note what happened in the jobcard's comments for the audit trail: recorded payments can't currently be edited or removed from the app.
Audit trail
Every change to the jobcard is recorded in the activity log, so even an amended invoice has a clean history of who changed what when.
If money has changed hands
Amending an invoice that's already been paid is awkward — make sure the customer is in the loop, especially if the new total is higher. Most amendments at that stage should be matched with a written explanation in comments.