How we review
your paperwork.
What goes into a Bill of Sale Check review, where the data comes from, how often we refresh it, what we are confident about, what we flag as inferred, and how we make money. Read this before paying so the output is calibrated, not magic.
The eight steps in a 30-second review.
Every paid review runs the same pipeline. State, document type, and the year of the vehicle change which rules fire — but the spine is identical for every transaction.
| Step | What happens | Where the data comes from |
|---|---|---|
| 1. Document parse | Your uploaded PDF or photo is OCR'd and structured into canonical fields (VIN, mileage, parties, price, date, signatures, terms, notary block). | Layout-aware OCR plus an LLM for field extraction; managed PDF-parse APIs are evaluated for production rollout. |
| 2. Federal compliance check | Programmatic rule engine: federal odometer disclosure (49 CFR §580) for vehicles under 20 model years, Truth-in-Mileage Act compliance. | NHTSA published rules. |
| 3. State compliance check | Programmatic rule engine against our state-rules database: notarization requirements, as-is language, sales-tax disclosure, witness requirements, title transfer venue and deadline. | State DMV websites + state statutes (cited per state, refreshed quarterly). |
| 4. Risk-flag detection | An LLM prompt analyzes payment-method scam vectors, vague delivery terms, missing odometer reading, price way above/below market, "as-is" without state-required disclosures. | LLM tool-use plus a rule library tuned on real-world fraud patterns. |
| 5. External lookups PLANNED | VIN-based recall lookup, state title-status checks where a public API exists, and a KBB-style private-party market price compare. Beta reviews are document-focused; these integrations roll out per the product spec (PRD §6.2). | NHTSA Recall API (free), state DMV APIs (where available), market-price provider (paid). |
| 6. Confidence labeling | Every finding is labeled High (verified by external source), Medium (parsed from your document with high accuracy), or Low (inferred / approximate). | See "Confidence intervals" below. |
| 7. Marked-up output | The original document is rendered with overlay annotations: red for critical, yellow for caution, green for confirmed-correct fields. | Server-side PDF rendering. |
| 8. Plain-English summary | The LLM summarizes findings in 50-80 words, plus a numbered "Action items before you sign" list. | LLM. |
Where the rules come from.
Every state-rule entry is sourced from an official state DMV publication or state statute. Federal rules are sourced from NHTSA. Market-price comparisons use Kelley Blue Book private-party value. We refresh on a published cadence and timestamp each entry.
| Federal odometer rule | 49 CFR §580 (Truth in Mileage Act)Sourced directly from NHTSA; refreshed when the rule changes (rare). |
|---|---|
| State DMV rules | Florida HSMV, Virginia DMV, Texas DMV, California DMV, Georgia DOR, Colorado DMVRefreshed quarterly; each rule is timestamped in our state-rules database. |
| VIN recall data PLANNED | NHTSA Recall LookupBundled VIN-recall lookup is part of the planned end-state pipeline (PRD §6.2). Beta reviews currently focus on document fields. |
| Title status PLANNED | State DMV public APIs (where available)Coverage varies by state; planned for rollout per state. Beta reviews flag title-related document fields without an external API call. |
| Market price PLANNED | Private-party market reference (KBB-style)Bundled market-price compare is planned for production rollout. Beta reviews surface the price field without an external comparison. |
| Scam-vector library | FTC consumer alerts + published industry fraud research + (over time) crowdsourced submissionsRefreshed as new patterns surface. |
What we know, what we infer.
Every finding ships with a confidence label so you can calibrate. Federal statutes are citable; market-price comparisons have intervals; payment-method risk assessment is informed inference, not certainty. We label accordingly.
| Confidence | What it means | Examples |
|---|---|---|
| High | Verified by an external authoritative source. | "Vehicle is under 20 years; federal odometer disclosure is required (49 CFR §580)." "Open NHTSA recall #25V-123 affects this VIN." "KBB private-party value is $11,800-$12,400; you're paying $13,200." |
| Medium | Parsed from your document with high accuracy and consistent across the document. | "Sale price field reads $13,200." "Odometer reading: 62,418 mi." "Seller's signature is present in the transfer block." |
| Low | Inferred or approximate; the field exists but the implication is judgment-based. | "Cashier's check on delivery is a known scam vector — we recommend you verify the check at the issuing bank before transferring keys." "As-is clause is buried in a paragraph; Florida requires it to be conspicuous." |
When the review can't help.
A bill of sale review is a paperwork check, not a vehicle inspection or a legal opinion. There are situations where we mark findings as "unable to verify" or hand the review back with a partial refund.
Document is illegible. If OCR can't extract the structured fields, we prompt for a re-upload. If a clean scan can't be produced, we partial-refund the review.
Document is not a bill of sale. If the upload is a different document (lease, insurance binder, registration), we detect and reject before running the review.
State we don't yet support. If the bill of sale is for a state outside our launch coverage (current: Florida, Virginia, Texas, California, Georgia, Colorado), we offer a "coming soon" hold + email capture and partial-refund the review.
VIN doesn't decode. If the VIN is malformed or unrecognized, VIN-dependent checks (recall, title status, market price) are flagged "unable to verify" and the rest of the review proceeds.
External APIs fail. If NHTSA, state DMV, or KBB can't be reached during the review window, the dependent finding is marked "unable to verify" and the rest of the review delivers normally.
How we make money & conflict-of-interest.
Bill of Sale Check is an independent paperwork-review tool. We are not a law firm, not a DMV, and not affiliated with any specific seller, dealer, lender, or insurer. Below is exactly how we make money so you can calibrate any recommendation we make.
Paid reviews ($24). One-time paid reviews are our primary revenue. The price is the same regardless of what we find. We don't charge more for "more issues" — that would be a structural conflict.
Affiliate referrals. When a finding leads you to a downstream service (vehicle history report, notarization, insurance quote), we may receive an affiliate fee from those vendors if you choose to use them. Affiliate links are disclosed inline and on every page that contains them. You are not required to use any affiliate; we surface the option, you decide. Specific partners include Carfax, AutoCheck (vehicle history), Notarize.com, Proof.com (notarization), The Zebra, EverQuote (insurance quotes).
What we don't do. We do not sell your uploaded document, your email address, your VIN, or any personal information. We do not get paid by sellers, dealers, lenders, or insurers to recommend specific transactions. We do not run paid placements within review output.
Document retention. Uploaded documents are encrypted in transit, used only to generate your review, and deleted from our storage after 30 days. Marked-up review PDFs you receive are yours; we keep a hash of the review for billing/dispute purposes only.
When we changed the rules.
Methodology updates and significant rule-database changes are logged here so anyone citing a Bill of Sale Check finding can confirm which version of the rules applied at review time.
2026-05-08 — Initial methodology page published. State-rules database covers Florida, Virginia, Texas, California, Georgia, Colorado at first-draft level; first quarterly paralegal review is scheduled before public-checkout launch.
2026-05-03 — Florida and Virginia state guides published; SEO state pages indexed.
2026-05-01 — Product positioning updated: end-state review pipeline targets bundled checks (VIN / title / price / payment + document compliance) per spec; private-beta scope is currently document-focused while integrations roll out.