Fraud prevention isn’t just a concern for large enterprises. Invoice and payment fraud is increasingly aimed at SMEs because processes are lean, approvals are informal, and changes slip through without verification.
The good news: most payment fraud isn’t sophisticated. It succeeds when basic checks aren’t built into the workflow. A few consistent controls prevent the majority of common fraud patterns without adding manual work.
The most common fraud patterns SMEs face
Before building controls, understand what you’re defending against:
| Fraud type | How it works | Why it succeeds |
|---|---|---|
| Supplier bank detail change | Scammer sends an email requesting updated bank details for a legitimate supplier | Finance updates the details without verifying via a known phone number |
| Urgent invoice bypass | “CEO needs this paid today” or “discount expires in 2 hours” | Urgency overrides normal approval process |
| Duplicate invoice payment | Same invoice submitted twice with slight variations | No duplicate detection in the payment process |
| Fake supplier creation | A fictitious supplier is added to the system and invoiced | No verification process for new suppliers |
None of these require technical sophistication. They exploit process gaps, not system vulnerabilities.
A practical fraud-prevention checklist
1. Verify changes to supplier bank details
Treat every bank detail change as high-risk, regardless of who requests it.
Minimum standard:
- Verify via a known phone number (not the number in the email requesting the change)
- Record who verified and when in the supplier record
- Never update bank details based solely on an email, even if it appears to come from a known contact
This single control prevents the most common and most expensive fraud pattern affecting Australian SMEs.
2. Use duplicate invoice detection
Duplicate payments happen when:
- An invoice is resent by the supplier (sometimes with a slightly different number)
- Different team members submit the same invoice through different channels
- A credit note is missed and the original invoice is paid again
Budgetly’s bill payments system flags potential duplicates before payment based on supplier, amount, and date proximity. A 30-second check before clicking “pay” prevents thousands in duplicate payments.
3. Separate request, approval, and payment
When one person can request, approve, and pay, fraud risk increases significantly. Even in small teams, try to:
- Require a second person for approvals above a defined threshold
- Log all approvals with timestamps and the approver’s identity
- Use approval workflows that route transactions to the right person automatically
You don’t need a complex hierarchy. Two people and a clear threshold is enough for most SMEs with 20-50 employees.
4. Create clear thresholds
Thresholds reduce “judgement calls” under pressure. When the rules are explicit, urgency can’t override them.
| Threshold | Action |
|---|---|
| Under $1,000 | Normal approval (budget owner) |
| $1,000 to $5,000 | Second approver required |
| Above $5,000 | Finance director or CEO approval |
| New supplier | Verification required before first payment |
| Bank detail change | Phone verification required |
These thresholds should be encoded in your spend management system, not just written in a policy document. Spend controls that enforce thresholds at the point of payment prevent the “just this once” exceptions that fraudsters rely on.
5. Watch for urgency cues
Fraud relies on urgency. The scammer needs you to act before you think.
Red flags that should trigger more checking, not less:
- “Pay today or we’ll lose a discount”
- “CEO needs this processed immediately”
- “New bank details attached, please update before next payment”
- “This invoice is overdue, please pay now to avoid penalties”
Train your team: urgency from an external source is a reason to slow down and verify, not speed up.
6. Run a weekly exception review
Track exceptions weekly as part of your standard spend review:
- Out-of-policy payments (transactions that bypassed normal rules)
- Rushed approvals (transactions approved faster than usual)
- Supplier changes (new suppliers added, bank details modified)
- Unusual patterns (same merchant appearing more frequently, round-number invoices)
The goal is to catch patterns early. A single anomaly might be nothing. Three anomalies in the same direction are a signal.
BB Disability & Health Services cut overspending by building a weekly review habit. The same discipline that prevents overspend also catches fraud patterns.
Controls that scale without adding headcount
The common objection to fraud prevention is “we don’t have the resources.” But the controls above don’t require additional staff. They require:
- Rules encoded in the system (spend limits, category restrictions, approval thresholds)
- Automatic enforcement (card declines for blocked categories, duplicate detection for bills)
- A weekly review habit (20 minutes, not a full-time role)
- Real-time visibility (so you see problems as they happen, not at month-end)
Directions Disability Support Services increased spending control and eliminated cash handling risk without adding admin overhead. The controls are built into the workflow, not layered on top of it.
The principle: make fraud harder, not admin heavier
The best fraud prevention is invisible to honest employees. Cards work at approved merchants. Approved spend flows without friction. Receipts are captured automatically. The controls only become visible when something falls outside the norm, and that’s exactly when you want them to be visible.
If your controls rely on memory and good intentions, fraud risk is higher than it needs to be. Encode the rules, automate the enforcement, and review the exceptions weekly.
