Independent review infrastructure

Co-presence confirmation
for service marketplaces.

A cryptographically sealed, tamper-evident record of a co-presence confirmation event — timestamped at the moment it occurs, independently held, independently verifiable by any party with the record and Vurno's published public key.

Book a 30-min intro How it works

"Vurno makes review fraud expensive. At scale, the pattern becomes visible in the audit trail."

The problem

Review fraud is accelerating.
Regulation has arrived.

89% of UK consumers rely on reviews when choosing services. Fake reviews are sold for $5 each on Telegram. The platforms that act earliest will win consumer trust — and pre-empt enforcement.

DMCC Act 2024 — enforcement is live

The Digital Markets, Competition and Consumers Act 2024 designates fake reviews as a banned practice under UK consumer law, with fines up to 10% of global annual turnover. The CMA completed a review of 100+ websites in July 2025 and wrote to 54 firms citing non-compliance. As of March 2026, it had opened five new investigations including Autotrader, Feefo, and Just Eat. The CMA's concern is not that platforms verify every review — it is that platforms take no reasonable structural steps to prevent manipulation. A Vurno co-presence record is that evidence.

£23bn
UK consumer spending influenced by reviews annually
89%
UK consumers who rely on reviews when choosing services
$5
Cost of an AI-generated fake review on Telegram channels
54
Firms written to by the CMA in July 2025 citing non-compliance
How it works

From job completion to sealed record in five steps.

The co-presence record is created at the moment the visit occurs — before any review is written. It cannot be retrospectively fabricated.

1

Register engagement

Your platform registers the engagement via the Vurno API before the visit begins.

2

Initiate event

When the tradesperson arrives, your platform signals the start of the confirmation window.

3

Confirmation initiated

In mobile mode, the consumer scans a QR code shown by the tradesperson. In integrator-vouched mode, your platform delivers the confirmation link via its own authenticated channel.

4

Consumer confirms

Mobile mode: Vurno sends a 6-digit OTP directly to the consumer's phone — suitable where your platform holds the consumer's phone number. Integrator-vouched mode: your platform delivers the confirmation via its own authenticated channel — suitable where you do not hold phone numbers or your privacy policy prevents sharing contact data with third parties. No contact data reaches Vurno in either case. The mode used is permanently recorded in the certificate.

5

Tamper-evident event record sealed

Vurno writes an Ed25519-signed entry to the append-only chain — each entry canonically serialised before signing. The certificate is delivered by webhook, with a mandatory independent email channel — durable delivery even if the webhook is temporarily unavailable.

Independence

We have no reason to favour anyone.

Vurno is not a directory. It has no listings, no tradesperson profiles, and no commercial relationship with any party on your platform. Its only function is to record whether a visit occurred.

That independence is the product. A co-presence record attached to a review is credible precisely because Vurno has no incentive to favour one platform, tradesperson, or outcome over another.

Stripe processes payments for Shopify and all of Shopify's competitors simultaneously. Shopify trusts Stripe because Stripe has no incentive to favour one merchant over another. Vurno is the same model for review integrity.

Append-only chain — sample entries
engagement.created
seq:0000 · identity_mode: co_presence
event.initiated
seq:0001 · event: visit_completion
qr_session.created
seq:0002 · ttl: 60s
event.confirmed
seq:0003 · verification_type: co_presence
engagement.status_changed
seq:0004 · status: confirmed · Ed25519 sealed
Precise positioning

What Vurno is — and is not.

Vurno raises the cost and friction of fraud. It does not eliminate it. That framing is accurate, defensible, and the limit of what we claim.

Not a review platform

Vurno never receives, stores, displays, or moderates review content. Its records are about whether a visit occurred. Where review events are posted to the chain, Vurno stores only hashes — never the review text.

Not a directory

No listings, no consumer search interface, no tradesperson profiles. Vurno is backend infrastructure — invisible to end users except for a single OTP confirmation moment.

Not a fraud guarantee

One or two fabricated records are theoretically possible. At scale, the co-presence pattern breaks immediately and is visible in the audit trail. Fraud becomes economically prohibitive, not impossible.

Not a consumer product

No consumer accounts. Consumers interact with Vurno once — the OTP confirmation page — then never again. The API is strictly backend-to-backend.

Trystan MacDonald, founder of Vurno
The founder

Why I built Vurno.

I'm Trystan MacDonald, founder of Vurno.

I started out as a mathematics teacher — a background that shaped my thinking around rigour, proof, and making complex systems legible to the people who have to stake something on them. I moved into software engineering full-time, spending over a decade as a senior and lead contract engineer across consumer platforms, regulated financial services, tier-1 investment banking, and telecommunications and public sector. Every one of those contexts had the same underlying requirement: systems where people need to be able to verify that what they are being shown is true. Vurno is the product that pulls that thread all the way.

Review fraud isn't a moderation problem. It's an economics problem. The cost of fabricating a review is a fraction of the value it delivers, and no badge scheme, manual check, or platform policy changes that equation. Every current solution is a soft control on top of a structurally broken incentive.

The only fix is raising the cost of fabrication itself — creating a record that existed before any review was written, independently held, and that cannot be backdated, amended, or bought. That's what Vurno is.

The DMCC Act 2024 has given platforms a deadline. The CMA is actively investigating. But the real reason to act isn't regulatory — it's that consumer trust in reviews is eroding, and the platforms that establish structural integrity first will be the ones consumers still trust in five years.

hi@vurno.co.uk
Design partner programme

Talk to us before your next compliance review.

Integrate with Vurno — so your customers know every review is backed by independent confirmation that the job happened.

A backend-only API integration — your platform pushes job events to Vurno, certificates come back by webhook. No consumer-facing UI required in mobile mode. For integrator-vouched mode, a single authenticated confirmation page is needed.

We run a 30-minute introduction call with engineering and product leads at qualifying marketplaces. No sales deck. Bring your questions.

Book an introduction call

Questions or integration enquiries — hi@vurno.co.uk

Engineering lead? Email for the OpenAPI specification — hi@vurno.co.uk