Document fraud detection you can actually buy

Run 50 of your own documents first

A pilot here is a free account and an afternoon. Create the account, with no card and no call, then send 50 documents from your own queue through the API, or through the checker while signed in. You get the same engine and the same signals as every paid plan. Send your decision rule with each API request in the X-Tamperlens-Policy header and the response carries the accept, review or reject that rule produces, next to the evidence for each signal. The account keeps a short record of each result, never the file or its text, which is what the dashboard history counts from; switch it off if you would rather keep nothing. The 50 documents renew every calendar month.

Count the documents it flagged that you would have passed, and the ones you would have caught anyway. If the numbers justify more volume, the next step is a credit pack or a plan. If they do not, you have spent nothing.

Create a free account

Start here: buy documents, not a subscription

A one-off payment for a bundle of documents that never expires, no card on file, nothing to cancel, no renewal date to diary. Most people screening documents do it in bursts, and this is the shape that fits a burst.

Your 50 free documents a month are spent first, every month, before a single credit is touched. Credits are the alternative to subscribing, so they are bought from a Free account, if a plan already covers your volume, you do not need them.

Or subscribe, when the volume is steady

Every plan runs the identical engine: you pay for volume only.

• The API is on every plan, including Free. There is no tier here where you may check a document by hand but not from your own code. A free key calls the same POST /api/v1/inspect the paid ones do, against the same engine and the same signal families.
• No monthly minimum. Nothing has to be committed before the first document is checked: the web checker is free and needs no account, the Free plan needs no card, and a credit pack is a one-off purchase with no floor under it. The cheapest way to check one document is to check one document.

Brazilian cards are charged in reais at checkout. These are the amounts you will be charged, not a conversion.

Which plan fits

No code needed. Sign in and drop files into the checker in your browser; each one counts against your plan. Or add Tamperlens to n8n with the official n8n node.

Past 50,000 a month, email me, I would rather talk about your volume than guess at a price for it.

What a check costs, against what a case costs

At the credit-pack rate a checked document runs $0.04 to $0.05. Here is the other side of that, using only numbers with a published method. The sources are named because a number you cannot check is worth nothing on a page like this.

• If you review documents inside a business. In the ACFE's 2026 Report to the Nations (2,402 investigated cases), the median occupational fraud loss was USD 104,000, and organisations under 100 employees carried the highest median of any size band at USD 126,000. In the same study the most common way fraud was concealed was creating or altering documents, and document examination was the first thing to catch it in 5% of cases.
• If you already have identity verification. DHS's Remote Identity Validation Rally tested seven commercial document-validation systems: false-accept rates ran from under 0.9% to under 76.7%. Two of the seven accepted roughly seven in ten forged documents. A neutral federal evaluator, not a vendor, and a reason "we're already covered" deserves a test rather than an assumption. Those systems read photographed ID cards, not PDF structure; the point is that the category is not solved, not that Tamperlens's numbers are theirs.
• If you operate in Brazil. The Fórum Brasileiro de Segurança Pública recorded 2,261,055 estelionato reports in 2025, and 2.8% of them produced a criminal proceeding. Where recovery through the courts is that unlikely, the control that remains is the one you apply before the transaction.

What none of this says is that a check prevents a loss. Tamperlens reports what a file's structure records, with the innocent explanation beside every finding; the decision, and the outcome, stay yours. The arithmetic worth doing is simply that the check is cheap and the case is not.

Private issuer baselines: the answer to a document that was never edited

Everything else on this site reads the record of editing: revisions appended after creation, a value retyped in a second font subset, an editor's name in the metadata. That works, and I publish how well. It has one blind spot, and I would rather sell you the counter than pretend the spot is not there.

A document generated cleanly from scratch carries no editing traces, because nothing was edited. Printed from a template, rebuilt as a flat image, emitted by a generator: the bytes are honest about their own history and silent about whose document it claims to be. That is the growth class in document fraud, and no byte-level engine catches it. Tamperlens included.

What does catch it is a reference: a structural profile of an issuer's genuine output, trained from documents you already hold and trust. How well that works depends on the issuer. Measured on published Brazilian documents, 6 of 7 public bodies with five or more contracts produce files consistent enough to profile, and 0 of 15 bank profiles do. Bank statements themselves have not been measured yet.

• Only fingerprints are stored. Training documents are read in memory and discarded like every other upload. See how that works.
• They are yours. A private baseline is visible to your key alone. The built-in public baselines work on every plan, including Free.
• Still signals, not verdicts. A mismatch says this file does not look like that issuer's output, with the differences named. A legitimate pipeline change looks the same, and the report says so.

Private baselines are on Team and up, and the API reference documents training and use. Whether a baseline catches a cleanly generated document has not been measured yet.