Trust & Transparency
Our Verification Methodology
SponsorShield's CoreFlux™ Risk Engine checks a UK Certificate of Sponsorship against 25+ fraud signals across four categories: UKVI sponsor register status, Companies House employer data, salary and SOC code validation against published thresholds, and PDF forensic analysis of the document itself. Each signal contributes to a single risk verdict delivered in under 60 seconds.
1. UKVI sponsor register check
We cross-reference the employer named on your CoS against the official Register of Licensed Sponsors, using fuzzy matching to account for minor name variations while flagging cases where no credible match exists. See our data sources page for how this data is sourced and refreshed.
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We check the employer's company registration status, incorporation date, and filing history via the Companies House API. A company that is dormant, recently struck off, or has no verifiable trading history adds to the risk signal.
3. Salary and SOC code validation
The salary stated on your CoS is checked against the current published threshold for the relevant SOC (Standard Occupational Classification) code, under both the general Skilled Worker route and the Health and Care Worker route where applicable.
4. PDF forensic analysis
We inspect the document's embedded metadata, font usage, and structural consistency to detect signs that the PDF was created or edited in consumer software (Word, Canva, Photoshop) rather than exported from an official system-generated record.
5. Verdict aggregation
Results across all four categories are combined into a single verdict: likely-valid, low-risk, suspicious, high-risk, fake, or inconclusive. The free tier shows a summary verdict; the full paid report breaks down every individual signal. See our step-by-step verification process for what happens after you upload a document.
SponsorShield is an independent verification support service. We are not OISC-regulated and do not provide immigration or legal advice. We are not affiliated with, endorsed by, or connected to UKVI, GOV.UK, the Home Office, or any UK government body. This guide is general information only — always consult an OISC-registered immigration adviser before making immigration decisions. Never pay anyone for a Certificate of Sponsorship.
Last reviewed: 2026-06-19. Data sources: UKVI Register of Licensed Sponsors (gov.uk), Companies House public register, published Home Office salary thresholds. This page is informational only and does not reflect real-time UKVI data — always cross-check current status on gov.uk before relying on it.
Published by SponsorShield. Reviewed for verification accuracy against current UKVI and Companies House data. Not immigration or legal advice.
Frequently Asked Questions
What is the CoreFlux™ Risk Engine?+
CoreFlux™ is SponsorShield's proprietary document analysis engine. It runs structured checks — UKVI register lookup, Companies House cross-reference, salary and SOC code validation, and PDF forensic analysis — and aggregates the results into a single risk verdict.
Does SponsorShield use AI to detect fraud?+
SponsorShield uses the CoreFlux™ Risk Engine, which combines rule-based checks against official data sources with structured document forensics (metadata inspection, font consistency, formatting analysis). The engine's logic is signal-based and auditable, not a black-box model.
How accurate is a SponsorShield risk verdict?+
Our checks are based on publicly available government and corporate records and document pattern analysis, not official UKVI verification. Results are a probabilistic risk indicator, not a guarantee of authenticity — see our full disclaimer for details.
What happens to my document after I upload it?+
Your PDF is analysed in server memory and permanently deleted immediately after your report is generated. It is never written to disk or stored in a database.
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