Top 25 Worst Companies in United Kingdom

United Kingdom Cybersecurity Risk Assessment - Lowest-Scoring Companies in 2026

Out of 7,729 companies in United Kingdom monitored by Rankiteo, this page highlights the Bottom 25 organizations with the weakest cybersecurity posture. These rankings are based on our proprietary Cyber Resilience Score, which integrates time-decayed incident exposure, sector-sensitive impact analysis, and market-cap-aware baseline and dampening to produce a single, interpretable score between 100 and 1,000.

Companies at the bottom of this ranking carry the heaviest accumulated cyber incident burden - including recent or severe ransomware attacks, data breaches with significant financial losses or records exposed, and repeated disclosure events. Understanding where these risk concentrations exist is essential for supply chain risk management, regulatory compliance, and competitive benchmarking within United Kingdom.

The current average score for the most notable companies in United Kingdom is 751.9 out of 1,000. Companies shown below score significantly lower than this average, falling far behind a country that generally maintains reasonable security standards.

Risk Highlights

How Cyber Risk Scores Are Calculated

Rankiteo's Cyber Resilience Score produces a single value between 100 and 1,000 for each organization, where higher scores indicate lower estimated cyber risk. The framework integrates three principal components that together balance evidence, context, and comparability across industries and company sizes. Learn more in our AI Cyber Score methodology.

Understanding the Risk Bands

Each score maps to a letter-grade band. Companies appearing in this lowest-scoring ranking typically fall in the bottom bands:

• Aaa (900-1,000): Exceptional cyber resilience - very few companies in a worst list reach this level.
• Aa (800-899): Very strong security posture with minimal weaknesses.
• A (700-799): Strong practices with some areas for improvement.
• Baa (600-699): Adequate protection but notable security configuration gaps exist.
• Ba (500-599): Below average - multiple risk areas require attention.
• B (400-499): Weak security with significant exposure across categories.
• Caa (300-399): Very weak with a high probability of exploitable vulnerabilities.
• Ca (200-299): Critically poor with severe, widespread security gaps.
• C (0-199): Extreme risk - immediate remediation is needed across all dimensions.

Why Monitoring Low-Scoring Companies in United Kingdom Matters

Cybersecurity risk doesn't exist in isolation. If your organization works with, purchases from, or shares data with companies in United Kingdom, their security weaknesses become your risk. Supply chain attacks - where adversaries compromise a less-secure vendor to reach a larger target - have become one of the most common and damaging attack vectors in recent years.

Rankiteo continuously monitors 7,729 companies in United Kingdom, keeping these rankings up to date so you always have an accurate, current picture of the country's risk landscape.

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