Fake Tax Document Detection API
Catch edited W-2s, rebuilt-from-Excel 1099s, and tampered P60s, T4s, Form 16, and NOA receipts in under 3 seconds. One REST call returns a deterministic verdict with named markers — no UI, no human review, no per-form configuration. The same endpoint handles every regional tax form because the analysis runs on the binary PDF structure, not the visual layout. Self-serve from $15/mo. No sales call.
The problem
Modern document fraud is invisible to visual review
A growing class of document fraud opens a genuine PDF, edits a balance, a date, or a beneficiary, and re-saves it. Visually nothing changes — the document passes pixel-level review, layout review, and KYC.
Structural PDF analysis reads the layers rendering engines never expose: revision history, object structure, signature coverage maps. That is where edits leave fingerprints they cannot wipe.
Common tampering patterns
- Modified balances or totals after export
- Swapped IBAN or beneficiary on invoices
- Post-signature edits on contracts
- Backdated issue and modification dates
- Fabricated documents from consumer PDF tools
What this looks like
How Tax Document Fraud Shows Up in the File
Three real fraud mechanics we catch at the structural PDF layer.
Edited employer payroll forms (W-2, P60, T4)
Real W-2s, P60s, and T4s come from payroll software — ADP, Paychex, Sage, Xero, and similar. When a fraudster edits values in a consumer PDF tool, the producer field changes from the payroll system to the editor. The API flags this producer mismatch as a high-confidence fraud marker.
Self-built 1099s and freelance income forms
Fake 1099-MISC and 1099-NEC forms used to inflate self-employment income are usually rebuilt in Excel and exported to PDF. The producer field exposes the spreadsheet origin instead of the legitimate IRS-form generator. Multiple revision layers and inconsistent fonts add structural evidence.
Tampered tax returns and assessment notices
Tax return PDFs, ITR receipts, and Notice of Assessment documents are often modified to inflate declared income for loan applications. Each edit appends an incremental update section to the cross-reference table. The API counts revision layers and returns the exact number detected.
Forged signatures on tax declarations
Some tax documents carry the issuing authority’s digital signature — HMRC, IRS e-file confirmations, EU national tax portal exports. If the signature was removed, replaced, or invalidated by post-signing edits, the API returns SIGNATURE_REMOVED or MODIFICATIONS_AFTER_SIGNATURE markers with certain confidence.
Tax-document fraud at the application layer
The detection gap
KYC platforms check the document. HTPBE? checks the file.
Two different checks — both matter.
KYC & identity platforms
Plaid · Persona · Alloy · Jumio
- Is this a real bank statement template?
- Does the account number match the identity?
- Is the document format consistent with the issuing bank?
Detects fake documents. Does not detect edited real documents.
HTPBE? tamper detection API
Structural PDF integrity
- Was this specific PDF file modified after it was generated?
- Do metadata timestamps match the file structure?
- Were digital signatures valid at the time of signing?
What HTPBE? checks
Detection capabilities
Deterministic structural signals. No probabilistic scores, no model training.
Producer signature mismatch
The PDF claims to come from one tool but the binary structure points to another. The first signal of post-export editing.
Incremental update trail
Every save after the original creates an incremental update. Long chains mean multiple editing sessions on the same file.
Multiple xref tables
Each editing session adds a new cross-reference table. Genuine institutional PDFs have one. Tampered PDFs have several.
Modification timestamp gap
A real PDF has matching CreationDate and ModDate. Months between them is a high-confidence forgery signal.
Digital signature validation
When a digital signature exists, we verify the coverage map. Modifications after signing return certain-confidence verdicts.
Font and object consistency
Edited text introduces new font subsets or objects with origin patterns inconsistent with the rest of the document.
Share with engineering
Wire this into your intake pipeline in under a day
Two API calls — one POST to submit the PDF, one GET to retrieve the verdict. Forward this page to your engineering team; the full API reference, quotas, and copy-paste examples in cURL, JavaScript, Python, PHP, Go, and Ruby are one click away.
Pricing
Self-serve plans, no sales call
All plans include the same forensic checks. Pick the quota that matches your monthly document volume.
manualStarter
$15/mo
30 checks/mo
Manual spot-checks and integration testing
most commonGrowth
$149/mo
350 checks/mo
Active document processing pipelines
high volumePro
$499/mo
1,500 checks/mo
High-volume automation and API integrations
Enterprise (unlimited, on-premise available) — see full pricing
API key on signup. Free test environment on every plan. No card required.
Customer Stories
Teams that stopped document fraud
Compliance, finance, and risk teams use HTPBE? to catch manipulated PDFs before they become costly mistakes.
Caught an invoice where the total had been changed by less than a thousand dollars. Without this I would have approved it without a second look.
Sarah M.
AP Manager
United States
We had three applicants in the same week with bank statements that looked completely fine. Two of them were flagged as modified. You simply cannot see this by reading the document — it is in the file structure.
Lars V.
Risk Analyst, Online Lending
Netherlands
Salary slips were coming with altered figures. We identified two problematic files before the placement was finalised.
Priya K.
HR Operations Lead
India
Since we started checking documents this way, we stopped two applications early in the process that would have been very difficult to reverse later.
Julien R.
Fraud Analyst, Fintech
France
Some applicants were sending PDFs that looked authentic but had been edited in ways not visible to the eye. We now ask for checked originals when something is flagged. Already saved us from a few bad decisions.
Marta S.
Compliance Coordinator
Spain
One invoice was caught because there was a mismatch between the document dates and structure. That particular case would have cost us significantly.
Tariq A.
Finance Manager
United Arab Emirates
FAQ
Frequently asked questions
Which tax forms does the API support?
Can it tell the difference between a real and a fake tax form?
How is this different from IRS or HMRC fraud detection APIs?
What confidence level does the API return on tax documents?
Secure your workflow
Create your account — API key on signup, free test environment on every plan.
From $15/mo. No sales call. Cancel any time.