AI Automation/Accounting

Use AI to Improve Fraud Detection During Audits

AI improves fraud detection by analyzing 100% of transactions for anomalies, not just a small random sample. It identifies subtle patterns like non-compliant journal entries or payments that fall just below approval thresholds.

By Parker Gawne, Founder at Syntora|Updated Mar 16, 2026

Key Takeaways

  • AI improves fraud detection by analyzing 100% of transactions for patterns that sampling misses, identifying outliers and subtle anomalies.
  • Custom AI models can detect issues like Benford's Law deviations, unusual journal entry timings, and payments to suspicious vendors.
  • An AI-driven system connects directly to client ledgers, flagging high-risk transactions for auditors to review.
  • A typical analysis of 100,000 transactions can run in under 5 minutes, augmenting rather than replacing the auditor's workflow.

Syntora builds custom AI fraud detection systems for small to mid-sized accounting firms that analyze 100% of client transactions. These systems move beyond manual sampling to identify complex anomalies missed by traditional methods. Drawing on direct experience building a PostgreSQL double-entry ledger, Syntora implements tests like Benford's Law analysis and outlier detection to flag high-risk entries for auditors.

Syntora has direct experience building accounting automation, including a PostgreSQL double-entry ledger with automated transaction categorization. For an accounting firm, this same expertise applies to building a system that ingests client ledger data and runs a series of forensic tests, flagging the most suspicious entries for an auditor's review.

The Problem

Why Do Accounting Firms Still Rely on Manual Fraud Detection?

Small and mid-sized accounting firms often rely on tools like ACL or even advanced Excel techniques for fraud detection. These tools require an auditor to manually script every single test. To run a Benford's Law analysis, you must export the data, load it, write the specific script, and interpret the static output. The process is repeated for every client and every type of test, with no learning or automation between audits.

Consider an auditor at a 20-person firm reviewing a client with 75,000 annual transactions. The standard practice is statistical sampling, which might cover only 1,500 entries. A fraudster making small, regular payments to a shell company for amounts just under the $10,000 senior review threshold will never be caught. The amounts are too small to appear in a high-value sort and too dispersed to be caught by random sampling.

Mainstream accounting software like QuickBooks or Xero offers basic controls, such as flagging duplicate invoice numbers. These systems are not designed for forensic analysis. They cannot correlate a journal entry's timestamp with employee office hours to flag entries made at 3 AM on a Saturday. They cannot connect to external vendor databases to verify a new supplier's legitimacy. The structural problem is that these tools are built for bookkeeping compliance, not active investigation. Their data models are rigid and cannot incorporate the external or behavioral signals needed to spot sophisticated fraud.

Our Approach

How Syntora Builds a Custom AI Fraud Detection Engine

The engagement would begin with a discovery process to understand your firm's current audit methodology and the accounting systems your clients use. Syntora would map your data access points, whether through direct database connections, API access to cloud accounting software, or secure file exports. The goal is to define a repeatable data ingestion pipeline that works across your client base.

The technical approach would use Python with the Pandas library to process and analyze 100% of the transactional data. Anomaly detection models, such as Isolation Forest from Scikit-learn, would identify outliers that manual review would miss. The system would execute a series of checks, including Benford's Law, duplicate payment analysis, and flagging journal entries with unusual descriptions or posting times. A custom model can be trained to recognize patterns specific to a client's industry, reducing false positives. The entire analysis pipeline would be deployed as an AWS Lambda function, capable of processing over 100,000 transactions in under 5 minutes for a hosting cost of less than $50 per month.

The delivered system provides a concise report or dashboard for each audit. Instead of searching for a needle in a haystack, your auditors receive a prioritized list of the top 50 most anomalous transactions. This allows them to focus their expertise on investigation and judgment, not manual data manipulation. The system slots into your existing workflow as a powerful preliminary analysis step.

Manual Audit SamplingAI-Assisted Audit Analysis
Statistical sampling of ~2% of transactionsComprehensive analysis of 100% of transactions
20-40 hours of manual data pulls and reviewUnder 15 minutes for an automated analysis run
High risk of missing low-and-slow fraud schemesFlags subtle patterns and cross-transaction anomalies

Why It Matters

Key Benefits

01

One Engineer From Call to Code

The person on the discovery call is the engineer who builds your system. No project managers, no handoffs, no miscommunication between sales and development.

02

You Own All the Code

You receive the full source code in your own GitHub repository, along with a runbook for maintenance. There is no vendor lock-in or proprietary platform.

03

A Realistic 4-Week Timeline

A custom fraud detection system of this scope is typically scoped and built within four to six weeks, depending on data access and complexity.

04

Transparent Post-Launch Support

After handoff, Syntora offers an optional flat monthly support plan for monitoring, maintenance, and model retraining. No surprise invoices.

05

Deep Accounting Data Experience

Syntora has built double-entry accounting ledgers from scratch. This firsthand experience with debits, credits, and journal entries means we understand your core data.

How We Deliver

The Process

01

Discovery and Scoping

A 30-minute call to discuss your current audit process and client data structures. You will receive a detailed scope document within 48 hours outlining the technical approach and fixed price.

02

Data Access and Architecture

You provide read-only access to anonymized sample data. Syntora designs the data pipeline and selects the appropriate anomaly detection models, which you approve before the build begins.

03

Iterative Build and Review

You receive weekly updates with initial findings from the system running on your sample data. Your feedback helps refine the models to reduce false positives and target relevant risks.

04

Handoff and Support

You receive the full source code, a deployment runbook, and documentation. Syntora monitors the system for 4 weeks post-launch, with optional ongoing support available.

The Syntora Advantage

Not all AI partners are built the same.

AI Audit First

Other Agencies

Assessment phase is often skipped or abbreviated

Syntora

Syntora

We assess your business before we build anything

Private AI

Other Agencies

Typically built on shared, third-party platforms

Syntora

Syntora

Fully private systems. Your data never leaves your environment

Your Tools

Other Agencies

May require new software purchases or migrations

Syntora

Syntora

Zero disruption to your existing tools and workflows

Team Training

Other Agencies

Training and ongoing support are usually extra

Syntora

Syntora

Full training included. Your team hits the ground running from day one

Ownership

Other Agencies

Code and data often stay on the vendor's platform

Syntora

Syntora

You own everything we build. The systems, the data, all of it. No lock-in

Get Started

Ready to Automate Your Accounting Operations?

Book a call to discuss how we can implement ai automation for your accounting business.

FAQ

Everything You're Thinking. Answered.

01

What determines the cost of a custom fraud detection system?

02

How long does a project like this take to build?

03

What happens after the system is handed off?

04

How do you handle sensitive client financial data?

05

Why hire Syntora instead of a larger agency or a freelancer?

06

What does our firm need to provide for the project?