Fake Tax Document Detection API
Catch edited W-2s and tampered P60s, T4s, Form 16, and NOA receipts in under 3 seconds – and keep 1099s rebuilt in Excel from passing as untouched originals. 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. 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)
When a fraudster edits the values on a real W-2, P60 or T4 in a consumer PDF tool, the editor typically leaves its fingerprint in the file. The API returns it as a high-confidence modification 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. However closely it copies the IRS form, a 1099 exported directly from Excel, with nothing indicating later editing, comes back INCONCLUSIVE – not INTACT – and should go to manual review; MODIFIED when the file itself carries evidence of editing or fabrication.
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 saved into the file leaves structural evidence, and the API returns it as a named marker.
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 HTPBE_SIGNATURE_REMOVED or HTPBE_POST_SIGNATURE_EDIT 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?
- Does the file carry evidence of editing after export?
- Were digital signatures valid at the time of signing?
What HTPBE? checks
Detection capabilities
Deterministic structural signals. No probabilistic scores, no model training.
Stated origin contradicted
The file’s structure contradicts the origin it states – a common sign of editing after export.
Post-creation edits
Detects documents that were changed and saved again after they were first produced, and reports them with a named marker.
Pages from multiple sources
Documents assembled from pages of different files – a page swapped in from another statement, a forged page spliced into a genuine pack.
Date inconsistencies
Creation and modification dates that contradict each other, or dates that could not be real. Either is a sign the file changed after it was issued.
Digital signature validation
When a document is digitally signed, HTPBE? checks whether it changed after signing or had its signature removed. Either finding returns a certain-confidence verdict.
Replaced or overlaid text
Detects text replaced or added on a page after the document was produced – without relying on how the page looks on screen.
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
30 credits/mo
Manual spot-checks and integration testing
most commonGrowth
350 credits/mo
Active document processing pipelines
high volumePro
1,500 credits/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?
inconclusive – not intact – and should go to manual review. A real tax form that was edited will be flagged because the modification creates structural evidence – dates that disagree, edits saved after issuance, and editing-tool fingerprints. Fully synthetic documents that were never real are a different problem and require visual or AI-based detection methods.How is this different from IRS or HMRC fraud detection APIs?
What confidence level does the API return on tax documents?
inconclusive and should go to manual review. When a digital signature was applied (common on EU and government-issued tax PDFs) and was later invalidated, the confidence is certain.Secure your workflow
Create your account – check PDFs on the web or with an API key, both ready on signup.
No sales call. Cancel any time.