Supported document type
Detect tampered and deepfake Loan Sanction Letter
A sanction letter is the bank's promise, before disbursement, to lend a stated amount on stated terms. Sellers and builders accept it as proof a buyer can pay, and visa and property files use it as evidence of funding. That is why fake sanction letters circulate: they cost nothing to produce, carry a letterhead and a reference number, and are rarely checked with the lender. The terms inside them are what give them away.
API slug: loan_sanction_letter
What a genuine loan sanction letter contains
A sanction letter is issued on the lender's letterhead to the borrower and any co-applicants. It states the sanctioned amount, whether the rate is fixed or floating, the tenure, the instalment, processing and other fees, the security offered, and conditions to be met before disbursement. A reference number and a validity date appear near the top, and an authorised signatory closes the letter, often with an acceptance block for the borrower.
The terms are linked. Amount, rate, and tenure determine the instalment, so a letter quoting an instalment that no schedule would produce is inconsistent with itself. The reference number follows the lender's own format, the validity date follows the issue date, and later documents such as the loan agreement and disbursement should carry the same figures. Branch and signatory details should exist at the institution named.
How loan sanction letter forgeries are made
Amount inflation
A genuine letter for a smaller loan has its amount raised to satisfy a seller or a proof-of-funds requirement. The instalment and fee lines then fail to match, and the edited digits differ in rendering from their line.
Wholesale fabrication
A letter is assembled on a real bank's branding with invented terms. Logos taken from a website carry their own compression and resolution, and the reference number often does not follow the lender's format.
Validity date extension
An expired approval is made current by changing its validity date. The changed date is a small text region, and its rendering seldom matches that of the letter's header.
Signature and stamp paste
An authorised signatory's mark is copied from another letter. Pasted marks keep the sharpness and tone of the source, and appear identical across documents that should have different signing dates.
What TamperCheck checks on a loan sanction letter
TamperCheck runs 200+ forensic checks across three layers and returns a risk score from 0 to 100 with plain-English findings tied to specific regions of the document. These three carry the most weight on this document class.
Arithmetic reconciliation
Stated totals are recomputed from their components, and running or cumulative figures are checked for continuity across periods. A single edited value breaks the chain even when the page still looks right.
Letterhead, logo, and issuer plausibility
Issuer branding is checked for resolution and compression consistency against the body text it sits on. A logo lifted from a website carries the signature of its source, not of the document.
Date and validity consistency
Issue, expiry, and period dates are checked against one another and against the file's own creation metadata, which catches backdating and validity extension.
And many more checks
The three above are the layers that carry the most weight on a loan sanction letter. Every upload runs the full suite of 200+ checks regardless of document class, spanning file structure and metadata, pixel-level forensics, font and text rendering, optical and print characteristics, provenance signals, AI-generation signatures, and many more checks.
Who verifies a loan sanction letter, and why
Property sellers, builders, banks, and immigration and visa reviewers. In each case the document is being used to unlock money, access, or a legal status, which is exactly what makes it worth forging.
How to verify a loan sanction letter in 4 steps
Check the fields against each other
Read sanctioned amount, interest rate and tenure, and reference number together rather than one at a time. Forgers typically change one value and leave the rest of the document describing the original.
Inspect the file metadata
Open the document properties and look at the producer, creation date, and modification date. A document produced by a consumer PDF editor, or created long after the date printed on its face, is worth a closer look.
Ask for a second document
Request a corroborating document from the same issuer or an adjacent period. Forgery effort concentrates on one file, so inconsistencies surface as soon as there are two to compare.
Run a forensic check
Manual review catches obvious edits but not field-level pixel manipulation or synthetic generation. TamperCheck runs 200+ forensic checks on a loan sanction letter and returns a risk score from 0 to 100 in about a minute, at $0.50 per document.
Frequently asked questions
How do sellers verify a buyer's loan sanction letter?
The reliable step is to ask the lender directly using contact details from an independent source. Before that, check that amount, rate, tenure, and instalment agree, that the reference and validity date look right, and that the letter's PDF shows no edited fields.
How can a fake bank sanction letter be detected?
Through inconsistency: terms that do not compute, branding at a different resolution from the text, a signature that repeats across documents, or a reference number in the wrong format. Forensic analysis of the file highlights the regions concerned.
Is a sanction letter a guarantee that a loan will be paid out?
No. It is an approval subject to conditions, usually including property valuation, documentation, and a validity window. That is one reason the terms matter more than the letter's appearance, and why it should agree with the loan agreement that follows.
What is the difference between a sanction letter and a loan agreement?
The sanction letter sets out approved terms before signing. The loan agreement is the binding contract, with security and default clauses. A mortgage file usually contains both, and the amount, rate, and tenure should be identical between them.
TamperCheck analyses loan sanction letter uploads with a hybrid forensic and AI pipeline tuned for this document class. Upload endpoints accept PDF and common image formats; class is inferred automatically. See the API documentation for authentication, async jobs, and webhooks.