How payment validation warnings work

When a document arrives, Nordflow compares its captured payment information against the supplier’s master data and against previous documents from the same supplier. If something has changed, a warning appears on the document.

What gets checked

Check	What triggers a warning
Bank account	The supplier’s bank account on this invoice differs from master data or the last invoice
Payment reference (FIK/KID)	The structured payment reference has changed
Document date age	The document date is more than three months old
Due date	The due date is more than three months in the future

Checks you cannot turn off

Two validations are always active regardless of your settings:

New supplier — a brand-new supplier always triggers a “new creditor” warning.
Master data mismatch — if the captured payment information disagrees with the supplier’s master data, a warning fires regardless of other settings.

These are core signals and cannot be disabled.

How a warning appears to an approver

When validation flags a document, a colored banner appears near the affected field in document details. An icon next to the field indicates the warning type. The approver can view the explanation — for example “Bank account changed since last invoice” — by hovering or clicking the icon.

The approver can still approve the document, but approving through a warning is logged in the activity history: who saw the warning, who chose to proceed, and when.

Why bank account changes are the most important check

Substituting a bank account on an otherwise normal invoice is the most common pattern in accounts-payable fraud. An attacker sends a legitimate-looking invoice from a real supplier but with a different bank account. Without automated comparison, this change is easy to miss in a busy approval queue. Nordflow’s bank account check catches this by comparing every incoming invoice against the supplier’s registered account, and flagging any difference for human review.