Delete a PENDING, PAID (gateway confirmation — never touched the balance) or CANCELLED financial transaction. Only SETTLED transactions cannot be deleted: a SETTLED transaction must be reversed first (it moved the balance). The parent title follows the fate of the remaining transactions: none left, the title is deleted as well (with its allocations and installments); all remaining CANCELLED, the title becomes CANCELLED; all remaining non-CANCELLED PAID, the title becomes PAID; otherwise the title remains and its balance is recalculated as the sum of the remaining PENDING transactions.