ACH fraud has been increasing steadily over the past several years, with cybercriminals using more advanced tactics to target businesses. Accounts payable (AP) teams are especially vulnerable because they manage sensitive banking information and vendor payments daily. One of the most common threats is vendor email compromise (VEC), where attackers manipulate payment instructions to redirect funds.
This guide explains how ACH fraud works, why vendor account update requests are risky, and what practical steps businesses can take to protect payment workflows.
Understanding the Rise of ACH Fraud
Automated Clearing House (ACH) payments are widely used because they are efficient and cost-effective. However, their growing adoption has also made them a major target for cybercriminals.
Why ACH Fraud Is Increasing
Fraud related to ACH payments has risen due to:
Increased reliance on digital payments
More remote communication with vendors
Higher transaction volumes
Weak internal verification procedures
Cybercriminals often exploit gaps in communication between finance teams and vendors.
The Role of Vendor Email Compromise (VEC)
Vendor email compromise is one of the most common ACH fraud tactics.
How VEC attacks typically work:
- Hackers gain access to a supplier’s email system
- They monitor invoices and payment timing
- They send a fake bank account update request
- The payment is redirected to a fraudulent account
- The account is quickly closed after receiving funds
These attacks often occur just before large scheduled payments, making them difficult to detect under pressure.
Why Vendor Bank Account Updates Are High-Risk
Vendor banking changes are routine in many industries, but they also present major fraud risks.
Frequency of Bank Account Changes
Suppliers commonly update bank accounts every few years due to:
Bank changes
Corporate restructuring
Operational adjustments
Most requests are legitimate—but attackers rely on this normal behavior to disguise fraudulent activity.
Real-World Fraud Patterns
Fraudulent update requests often share warning signs such as:
Urgent payment instructions
Requests shortly before large payments
Changes sent through email only
Pressure to bypass verification procedures
These tactics are designed to exploit time-sensitive payment cycles.
Secure Ways to Collect Vendor Banking Information
Protecting ACH payment data begins at the moment vendor information is collected.
Avoid Email-Based Data Sharing
Email is one of the least secure channels for transmitting banking details.
Sensitive information should never be shared through:
Plain-text email
Unsecured attachments
Unverified messaging channels
Instead, companies should implement secure alternatives.
Use Secure Vendor Portals
Secure portals provide safer communication channels for banking details.
Benefits include:
Encrypted data transmission
Authentication controls
Audit tracking
Centralized documentation
These systems significantly reduce the risk of intercepted data.
Implement Phone Verification Procedures
When collecting data over the phone, identity verification is essential.
Best practices include:
Calling verified supplier contacts
Confirming identity using security questions
Recording confirmation logs
Avoiding acceptance of unsolicited calls
This ensures the person providing information is authorized.
Validating Vendor Banking Details
Validation is one of the most important steps in preventing fraudulent payments.
Use Multi-Step Verification
Before processing any payment update:
Confirm bank changes using a second communication channel
Verify information with procurement records
Require documented approval workflows
Multi-step verification reduces the likelihood of unauthorized changes.
Work with Third-Party Validation Tools
Many companies use external tools that connect directly to banking systems.
These tools help verify:
Account ownership
Routing number validity
Account status
Institution legitimacy
Third-party validation improves accuracy and reduces manual errors.
Cross-Check Existing Vendor Records
For existing vendors, compare new banking details against historical records.
Useful cross-check methods include:
Matching account names
Verifying transaction history
Confirming contract documentation
Even small discrepancies can indicate fraud.
Securing Stored Vendor Data
Once vendor banking data is collected and verified, secure storage becomes critical.
Limit Access Permissions
Only authorized personnel should have access to sensitive financial data.
Access controls should include:
Role-based permissions
Authentication requirements
Activity monitoring
Periodic access reviews
This reduces the risk of insider threats and unauthorized exposure.
Protect Physical Records
Although many companies operate digitally, physical documents still exist.
Best practices include:
Locking files in secure cabinets
Restricting document access
Avoiding unsecured storage locations
Maintaining document logs
Physical security remains important in hybrid work environments.
Secure ERP System Storage
Many organizations store vendor banking details in Enterprise Resource Planning (ERP) systems.
To secure ERP storage:
Enable strict permission workflows
Monitor user access activity
Conduct frequent security audits
Use encrypted data storage
Proper configuration protects sensitive vendor information.
Building Strong Internal Fraud Prevention Processes
Technology alone cannot eliminate ACH fraud risk. Structured internal procedures are equally important.
Train Accounts Payable Teams
Employee awareness is one of the strongest fraud defenses.
Training topics should include:
Recognizing phishing attempts
Identifying suspicious requests
Following verification protocols
Reporting unusual activity
Regular training ensures teams remain alert.
Standardize Payment Change Procedures
Every banking update should follow consistent rules.
Standard procedures may include:
Formal request documentation
Dual approval requirements
Mandatory verification calls
Secure audit logging
Consistency reduces human error.
Partner With IT and Security Teams
Finance teams should collaborate closely with IT departments.
Joint responsibilities include:
Network security monitoring
Encryption management
Threat detection systems
Incident response planning
Cross-department cooperation strengthens security posture.
Why Secure ACH Processes Matter During Digital Transformation
Many companies are transitioning from paper checks to electronic payments. While this improves efficiency, it also introduces new vulnerabilities.
Risks During Rapid Payment Modernization
Organizations shifting to digital payments may overlook:
Security configuration steps
Vendor validation procedures
Data storage protections
Access management controls
Speed should never replace security.
Outsourcing Payment Security When Necessary
Some businesses lack internal resources to manage complex payment security systems.
In such cases, outsourcing to specialized providers may help:
Improve payment monitoring
Reduce fraud risk
Strengthen compliance
Enhance operational efficiency
Outsourcing can be effective when implemented carefully.
Preparing for Future ACH Fraud Threats
Cyber threats continue to evolve, and payment systems must adapt accordingly.
Plan for Worst-Case Scenarios
Businesses should conduct risk assessments to identify vulnerabilities.
Preparation strategies include:
Creating incident response plans
Running fraud simulations
Testing backup systems
Maintaining recovery protocols
Preparation reduces damage when incidents occur.
Continuous Monitoring and Improvement
Fraud prevention is an ongoing process.
Key actions include:
Reviewing payment logs
Updating verification policies
Auditing access controls
Monitoring emerging threats
Security must evolve alongside technology.
Conclusion
ACH fraud remains one of the most serious threats facing modern finance teams, especially as digital payments become more widespread. Vendor email compromise attacks and fraudulent bank account changes are among the most common tactics used by cybercriminals.
By implementing secure data collection methods, validating vendor information thoroughly, protecting stored banking data, and training staff effectively, businesses can significantly reduce the risk of payment fraud. Strong processes, combined with secure infrastructure, create a resilient payment environment that protects both financial assets and vendor relationships.
