Issued invoice
Also called Sent invoice · Immutable invoice · Frozen invoice
TL;DRAn invoice that has been finalised or sent — and will never gain, lose, or change a line.
Once a document is issued it is what the customer has. Sonic will not pile a later charge onto it, and it will not silently rewrite a rate. A later charge becomes a new invoice alongside; a correction becomes a credit note or an adjustment invoice.
This is the rule that makes the trail auditable: what was sent is what is stored, and every subsequent change has its own document.
Where it happens in Sonic
Next
See it on your contracts
A walkthrough on the agreements and files you actually bill from — not a slide deck.