ThumbPrint is MoneyThumb's patented fraud detection engine for PDF documents. It analyzes a bank statement and returns a score indicating how likely it has been altered or fabricated, along with the specific factors behind the score.
ThumbPrint is built to catch statement-level tampering—signs that a real document was edited or that a document was fabricated to imitate a real one. Concretely, it surfaces patterns, such as:
- Altered dollar amounts or modified account balances.
- Copied or duplicated transaction lines.
- Fonts that are inconsistent with a bank's known statement template.
- Layout or formatting anomalies relative to that bank's established structure.
It does not attempt to verify the borrower's underlying financial situation. See Known Limitations below.
ThumbPrint uses AI and machine learning to detect inconsistencies both within a single statement and across the population of statements MoneyThumb has processed from that same bank, effectively building a "ThumbPrint" of what genuine statements from that institution look like.
Both analyses feed into a single weighted score.
The underlying technique is patented (US Publication No. 2023/0359815, "Detection of Altered Documents"). We don't publish the specific factor set or weighting logic since that's the proprietary part, but the patent filing describes the general architecture.
| Score | Meaning | Suggested Action |
|---|---|---|
| -1 | Not scorable. Typically, an image-based PDF rather than a native document. Insufficient data to analyze. | Route for manual review or request a native file. |
| 0 | No abnormalities found. | Proceed normally. |
| 1–299 | Low risk | Proceed normally. Spot-check at your discretion. |
| 300–700 | Moderate risk | Flag for a closer look before final decisioning. |
| 701–999 | High risk | Escalate to manual review before proceeding. |
| 1000 | Direct evidence of editing. | Treat as confirmed alteration. Escalate accordingly. |
These bands are a starting point. Some customers tune their internal thresholds (e.g., where "flag for review" begins) based on their own risk tolerance and portfolio performance.
Any score above 0 comes with a list of the specific factors that contributed to it. Rather than routing to the same queue, teams can use the factors to route intelligently. Where available in our Insights UI, the View in PDF link highlights the exact location in the document tied to a factor, which shortens manual review time considerably.
| Approach | What it catches | What it misses |
|---|---|---|
| Manual Review | Whatever a trained reviewer happens to notice. | Inconsistent, slow, doesn't scale, misses subtle structural tampering. |
| Rules-Based/Metadata Checks | Simple edit markers, "last modified" flags. | Anything where metadata has been scrubbed or the file re-saved. |
| Statement Issuer Verification (e.g., direct login to the bank) | Ground-truth confirmation the account exists and matches. | Costly, slow, raises privacy/liability concerns and applicants often decline to grant access. |
| ThumbPrint | Structural tampering and fabrication signals that survive metadata scrubbing at automated scale. | See Known Limitations. |
ThumbPrint is a statement-integrity check, not a full financial or identity investigation. Be aware of what it isn't designed to do:
- It can't tell you the applicant is lying about their financial picture using real documents. A borrower who submits genuine, unaltered statements — but only the flattering ones, omitting other accounts — won't trigger a high score, because nothing in those documents was tampered with.
- It can't catch a fabricated institution it has no history with. The inter-document model relies on having seen prior genuine statements from that bank. A convincing fake from an obscure or newly-fabricated "bank" may score lower than expected until MoneyThumb builds a baseline for it.
- It operates at the statement level, not the account or identity level. It won't detect account takeover, identity fraud, or synthetic identities — only whether the document itself appears authentic.
- Scores can start high on legitimate new formats. When a bank changes its template, or a new bank is introduced, early scores may run higher than warranted until ThumbPrint learns the new baseline — expect some early false positives on genuinely new formats.