I Compared All 30+ UK Energy Suppliers by Customer Service – Data Rankings

Last updated: January 24, 2026 | Reading time: ~10 minutes

Why I Did This Comparison

When I first moved to the UK in October 2025, I searched for “best UK energy provider” and got overwhelmed. Every article focused on price comparisons – unit rates, standing charges, fixed vs variable.

But after my gas got capped by Cadent within my first month, I learned something important:

When things go wrong, customer service matters more than saving £50/year.

I spent weeks trying to resolve that issue. Couldn’t get through to anyone. Emails went unanswered. The experience was miserable.

So I decided to answer a question using real, verified data instead of opinions:

Which UK energy suppliers actually treat customers best when you need help?

I analyzed three independent data sources to remove any single-source bias:

• Which? Magazine (September-October 2025 survey of 11,945 customers)
• Ofgem (Official complaints data Q3 2025)
• Trustpilot (Verified customer reviews, accessed January 2026)

No affiliate bias. No personal anecdotes. Just numbers.

Data Sources Used (Transparency First)

Primary Source: Which? 2025/26 Energy Survey

• Sample size: 11,945 UK energy customers surveyed
• Time period: September-October 2025
• Methodology: Independent consumer survey + behind-the-scenes assessment
• Source: Which? Energy Company Survey Results
• Accessed: January 20, 2026

Secondary Source: Ofgem Complaints Data

• Metric: Complaints per 100,000 customer accounts
• Time period: Q3 2025 (July-September 2025)
• Source: Ofgem Customer Service Data Portal
• Accessed: January 20, 2026

Tertiary Source: Trustpilot Customer Reviews

• Reviews analyzed: 154,000+ verified UK energy customer reviews
• Rating scale: 1-5 stars
• Source: Trustpilot UK Energy Suppliers
• Accessed: January 21, 2026

Supporting Data: Citizens Advice Star Rating

• Metric: Composite score (complaints, contact time, customer commitment)
• Time period: Q2 2025 (April-June 2025)
• Source: Citizens Advice Energy Supplier Comparison
• Accessed: January 21, 2026

Data limitation: Smaller suppliers have fewer reviews, which I note where relevant. All data is publicly available and verifiable through the linked sources.

How This Analysis Works (Methodology)

I didn’t just pick my favorite suppliers. Here’s exactly how I analyzed the data:

Which? Magazine Scoring System:

Which? combines two scores for each supplier:

1. Customer Score (0-100%):

   • Based on customer satisfaction survey
   • Likelihood to recommend
   • Ratings on: customer service, value for money, bill clarity, ease of contact

2. Which? Assessment Score (0-100%):

   • Complaints performance (30% weight)
   • Contacting your supplier (25% weight)
   • Supporting vulnerable customers (25% weight)
   • Smart meter performance (10% weight)
   • Switching processes (10% weight)

3. Total Score: Combination of both scores

Ofgem Complaints Metric:

• Number of complaints per 100,000 customer accounts
• Lower is better (fewer complaints = better service)
• Market average Q3 2025: 1,027 complaints per 100k accounts

Trustpilot Rating:

• Average star rating (1-5 stars)
• Based on verified customer reviews
• I prioritized suppliers with 1,000+ reviews for reliability

🏆 Top-Ranked UK Energy Suppliers (Customer Service)

Based on the comprehensive Which? 2025/26 survey, here are the Which? Recommended Providers – suppliers that excelled across all metrics:

Tier 1: Which? Recommended Providers (74%+)

Source: Which? Energy Survey 2025, published January 2026

Why These Four Stand Out:

E (Gas & Electricity):

• Achieved the highest Which? assessment score of any provider
• Particularly strong for complaints handling, smart meters, and switching
• Specializes in prepayment meters
• Received 3-4 star ratings across all customer service categories
• Note: This is their second time as Which? Recommended Provider (first was 2024)

Octopus Energy:

• Nine consecutive years as Which? Recommended Provider
• 4.8/5 on Trustpilot from 154,000+ verified reviews
• Now UK’s largest energy supplier (24.6% market share as of Q1 2025)
• Maximum points for supporting vulnerable customers
• Known for innovative tariffs (Agile, Go, Intelligent Octopus for EVs)

100Green:

• Ranked #1 in Citizens Advice Q2 2025 star ratings
• 80% customer satisfaction score
• Achieved 5/5 for complaints (lowest complaint ratio)
• Caveat: Scored lower on vulnerable customer support (not signed Energy UK Vulnerability Commitment)

Utility Warehouse:

• Gained 0.1 percentage points market share in past year (while most lost market share)
• 4.6/5 on Trustpilot
• Strong on bundled services (energy + broadband + mobile)
• UK-based call centers
• Excellent for customers who prefer phone support

⚠️ Lowest-Ranked Suppliers (Service Issues)

Based on Which? 2025/26 survey, these suppliers received overall scores below 60% and consistently poor customer ratings:

Tier 4: Underperforming Suppliers (<60%)

Source: Which? Energy Survey 2025

What The Data Actually Shows:

Scottish Power (56% - Lowest Overall):

• Received the lowest score for complaints handling of any provider assessed
• 2 stars out of 5 for: customer service, value for money, billing, ease of contact
• Their response: Points to Citizens Advice scorecard (different methodology) and 4.8 Trustpilot rating
• My analysis: Trustpilot rating conflicts with Which? and Ofgem data – suggests possible review management

EDF Energy (58%):

• Worst score for “contacting your supplier” category (3 out of 12 points)
• Phone lines and email not monitored as long as other providers
• 2 stars from customers in every category
• Trustpilot: 4.8/5 (but see note on Scottish Power above)

British Gas (59%):

• Despite investment in customer service, still underperforming
• 0 out of 5 for switching practices (lowest possible score)
• High complaint volumes despite being 2nd largest supplier
• Positive note: Complaints fell by 20% year-over-year (2024-2025)
• 1.8/5 on some consumer review sites

Ovo Energy (59%):

• Lowest customer satisfaction score at 56%
• Now UK’s 3rd largest energy provider
• 2 stars for: value for money, communication, overall service
• Customers particularly dissatisfied with communication

📊 The Ofgem Complaints Data (Q3 2025)

Here’s what the official regulatory data reveals about complaint volumes:

Market-Wide Complaints:

• Market average: 1,027 complaints per 100,000 customer accounts (Q3 2025)
• Large suppliers average: 1,026 per 100k accounts
• Medium suppliers average: 1,321 per 100k accounts (highest)
• Small suppliers average: 233 per 100k accounts (lowest)

Key finding: Small suppliers consistently receive far fewer complaints relative to customer base.

Source: Ofgem Customer Service Data, Q3 2025

Complaints Trend:

• Market complaints down 30% from Q3 2024 to Q3 2025
• Large suppliers: down 33% year-over-year
• This is the lowest complaint rate since tracking began

What This Means:

The energy market’s customer service is improving overall. But there’s still a 4x difference between best and worst performers.

🔍 One Chart That Tells The Story

Looking at the Which? 2025/26 survey results, there’s a clear pattern:

Top performers share these characteristics: ✅ Digital-first approach (but with human backup) ✅ Transparent pricing and billing ✅ Proactive communication ✅ Fast complaint resolution ✅ Investment in technology (apps, online accounts)

Bottom performers share these problems: ❌ Long wait times to reach customer service ❌ Slow complaint resolution ❌ Poor communication about issues ❌ Limited contact channel options ❌ Legacy systems causing billing errors

The Price vs Service Paradox:

This is crucial for newcomers to understand:

The cheapest tariffs often belong to the worst service performers.

Example from the data:

• British Gas often has competitive pricing
• But ranks 3rd from bottom for customer service
• If you have a billing dispute, you might spend weeks resolving it
• The £60/year you “saved” costs you hours of stress and lost productivity

What This Means If You’re New to the UK

As someone who arrived recently and learned this the hard way, here’s what I wish I’d known:

Prioritize These Factors (In Order):

1. Low Complaints Per Customer (Most Important)

• Check Ofgem data: aim for below 1,000 complaints per 100k
• Look at Which? assessment scores
• Citizens Advice star ratings

2. Responsive Customer Support

• Can you reach them when you need to?
• Average wait times under 5 minutes
• Multiple contact channels (phone, email, app, live chat)

3. Clear Online Account Management

• Can you submit meter readings easily?
• Can you see your usage and bills clearly?
• Is there a working mobile app?

4. Then Consider Price

• After the above are satisfied, compare rates
• Use comparison sites: Compare The Market, Uswitch
• Look for fixed deals cheaper than the price cap

For International Students & Newcomers Specifically:

Based on the data, I’d recommend in this order:

Best for newcomers who want reliability:

1. Octopus Energy – Proven track record, excellent app, clear communication
2. Utility Warehouse – Good if you also need broadband/mobile, UK call centers
3. E (Gas & Electricity) – Especially if you have a prepayment meter

Approach with caution:

• British Gas (name recognition ≠ good service)
• Scottish Power (despite high Trustpilot rating)
• EDF Energy (hard to reach when you need help)

My Data-Backed Recommendations

After analyzing all this data, here’s what I recommend:

Best Overall for Newcomers:

→ Octopus Energy

Why:

• Highest consistency across all datasets (Which?, Ofgem, Trustpilot, Citizens Advice)
• 9 years running as Which? Recommended Provider
• 4.8/5 from 154,000+ verified reviews
• Excellent mobile app (crucial when you’re new and on-the-go)
• Clear, transparent billing
• Fastest growing supplier (people vote with their feet)

Best If You Prefer Phone Support:

→ Utility Warehouse

Why:

• UK-based call centers
• Bundle services (energy + broadband + mobile) – fewer companies to deal with
• Good for people who aren’t comfortable with apps/online-only
• Solid complaint handling

Best for Prepayment Meters:

→ E (Gas & Electricity)

Why:

• Specialist in prepayment meters
• Highest Which? assessment score
• 4.8/5 on Trustpilot
• Understanding of prepay customer needs

Best Budget Option (If Service Is Secondary):

→ Check comparison sites for current fixed deals

If you:

• Are confident handling issues yourself
• Rarely need customer support
• Prioritize saving money above all

Then use: MoneySuperMarket, Compare The Market, Uswitch

These are affiliate links - I may earn a commission at no extra cost to you.

Who To Approach Cautiously:

Based purely on the data:

• British Gas – High complaint volumes despite improvements
• Scottish Power – Worst complaints handling score
• EDF Energy – Hard to contact when you need help
• Ovo Energy – Lowest customer satisfaction score

Important note: These companies serve millions of customers. Many people have perfectly fine experiences. But statistically, you’re more likely to have service issues with these suppliers than with top-ranked ones.

The Full Rankings Table

Here’s the complete Which? 2025/26 survey results for all major suppliers:

Sample sizes for customer score: E (92), Octopus Energy (2,708), 100Green (146), Co-op Energy (112), Sainsbury’s Energy (79), Outfox Energy (74), Good Energy (78), Utility Warehouse (291), Utilita (323), Ecotricity (115), Fuse Energy (112), E.ON Next (1,663), Ovo Energy (1,011), So Energy (108), British Gas (3,179), EDF Energy (1,123), Scottish Power (780).

Source: Which? Magazine, September-October 2025 survey of 11,945 energy customers

Key Takeaways (TL;DR)

After spending hours analyzing this data, here’s what you need to know:

Main Findings:

1. Customer service quality varies dramatically between suppliers

   • Best vs worst: 77% vs 56% (21 percentage point gap)
   • That’s the difference between “excellent” and “poor”

2. Legacy “Big Six” brands underperform despite name recognition

   • British Gas, Scottish Power, EDF all scored below 60%
   • Brand familiarity ≠ good service

3. Small/medium suppliers often outperform giants

   • 233 complaints per 100k (small) vs 1,026 (large)
   • More agile, better technology, more focused on service

4. Digital-first suppliers lead in customer satisfaction

   • Octopus, E, 100Green all have excellent apps
   • Fast response times, transparent communication

5. Complaints data more reliable than marketing claims

   • Ofgem data = regulatory requirement, verified
   • Trustpilot ratings can be gamed
   • Which? independent consumer survey most trustworthy

6. Newcomers benefit most from service-first providers

   • When you don’t understand the UK system yet
   • When you might need to call and ask “stupid questions”
   • When you need someone patient on the phone
   • Service quality > £50/year savings

What I Wish I’d Known In Month 1:

• Don’t choose based on price alone
• Check Which? ratings before switching
• Read recent Trustpilot reviews (not just the star rating)
• Ask other newcomers what their experience has been
• Be willing to pay slightly more for better service initially
• You can always switch later once you understand the system better

How To Use This Data When Choosing

Here’s my step-by-step process based on this research:

Step 1: Identify Your Priority

Are you:

• Service-focused: Choose from Which? Recommended Providers
• Budget-focused: Use comparison sites, accept possible service trade-offs
• Bundle-focused: Consider Utility Warehouse for multi-service discounts

Step 2: Check Multiple Sources

For your shortlisted suppliers:

1. Which? ratings (service quality)
2. Comparison sites for price (MoneySuperMarket, etc.)
3. Recent Trustpilot reviews (last 3 months)
4. Citizens Advice complaints data

Step 3: Calculate Total Value

Don’t just compare annual costs. Consider:

• Time value: What’s your time worth if you spend 5 hours resolving a billing issue?
• Stress value: Is £60/year worth the frustration of poor service?
• Certainty value: Is it worth paying more for reliable, predictable service?

Step 4: Start With Recommended Providers

For your first UK energy contract, I genuinely recommend:

• Start with a Which? Recommended Provider
• Get a 12-month fixed deal (not longer – market changes)
• Learn how the UK energy system works
• Reassess in 12 months with more knowledge

Step 5: Set a Review Reminder

• Add a calendar reminder 2-3 months before contract end
• Research current deals at that time
• Switch if better option available
• Don’t just auto-renew

Data Limitations & Caveats

In the interest of transparency, here’s what this data can’t tell you:

What This Data Doesn’t Account For:

Individual Variation:

• Your specific usage patterns might favor different tariffs
• Your location affects standing charges (regional variation)
• Your payment method affects rates (direct debit vs prepay)

Recent Changes:

• Supplier performance can improve/decline between survey waves
• New suppliers launched since survey (not enough data yet)
• Market conditions change (energy crisis recovery period)

Personal Factors:

• How comfortable you are with technology (app vs phone)
• Whether you need specialist support (vulnerable customer programs)
• Whether you want 100% renewable energy (green tariffs)

Use This Analysis As:

✅ Context for understanding patterns across the market ✅ Timing guidance for when providers typically perform well ✅ Benchmarks for evaluating deals you find ✅ Risk assessment for service quality likelihood

Don’t Use As:

❌ Guaranteed predictions – past performance ≠ future results ❌ Only factor in decisions – price, tariff type, contract length matter too ❌ Substitute for personal research – read recent reviews, check current offers ❌ Financial advice – I’m not a financial advisor, this is data analysis

All Sources & Methodology Notes

Primary Data Sources:

1. Which? Magazine Energy Survey 2025/26

   • Full URL: https://www.which.co.uk/reviews/energy-companies/article/energy-companies/which-energy-survey-results-ajqM43e6ycY8
   • Accessed: January 20, 2026
   • Sample: 11,945 UK energy customers
   • Survey period: September-October 2025

2. Ofgem Customer Service Data Portal

   • Full URL: https://www.ofgem.gov.uk/news-and-insight/data/data-portal/customer-service-data
   • Accessed: January 20, 2026
   • Metric: Complaints per 100,000 customer accounts
   • Period: Q3 2025 (July-September 2025)

3. Trustpilot UK Energy Suppliers

   • Full URL: https://uk.trustpilot.com/categories/energy_supplier
   • Accessed: January 21, 2026
   • Reviews analyzed: 154,000+ verified reviews
   • Focus: Recent reviews (Q4 2025 - Q1 2026)

4. Citizens Advice Energy Supplier Star Rating

   • Full URL: https://www.citizensadvice.org.uk/consumer/your-energy/get-a-better-energy-deal/compare-domestic-energy-suppliers-customer-service/
   • Accessed: January 21, 2026
   • Period: Q2 2025 (April-June 2025)
   • Metric: Star rating (1-5) across complaints, contact time, commitments

5. NimbleFins Energy Supplier Analysis

   • Full URL: https://www.nimblefins.co.uk/best-and-worst-energy-suppliers
   • Accessed: January 21, 2026
   • Supporting data on market share and performance

Methodology Notes:

All calculations, analysis, and conclusions are my own work based on these official sources.

Data current as of: January 24, 2026

Next update expected:

• Which? survey: Likely September-October 2026
• Ofgem complaints: Quarterly (next Q4 2025 data in January 2026)
• I’ll update this post when new data becomes available

Related Analysis

Coming up in this series:

📊 I Analyzed Ofgem Complaint Data By Provider – Which Cause Most Problems (Publishing Feb 2026)

🎓 Best UK Energy Provider for International Students 2026 (Publishing Feb 2026)

📈 I Tracked 5 Years of Price Cap Data – Patterns Revealed (Published Jan 2026)

⚡ Standing Charges By Region – Complete UK Analysis (Publishing Feb 2026)

Final Thought

After moving to the UK and experiencing both good and bad customer service firsthand, I’ve learned this:

Understanding beats prediction. Data beats assumptions.

The energy market is complex, and as a newcomer, you’re at a disadvantage. The suppliers know this.

That’s why I spent hours compiling this data. To level the playing field.

My advice based on everything I’ve learned:

• Start with a Which? Recommended Provider
• Get experience with the UK energy system
• Learn what matters to you (price vs service vs green energy)
• Switch strategically when you understand your usage

Don’t get paralyzed by choice. Pick a good supplier from the top of this list, get a 12-month deal, and revisit in a year with more knowledge.

The best choice is the one that lets you stop worrying about energy and focus on settling into your new life in the UK.

Have questions about this analysis? Spotted an error in my data? Let me know in the comments. I read every one and update posts when better information becomes available.

Update log:

• January 24, 2026: Initial publication
• [Future updates will be noted here]

💡 Ready to Compare Energy Deals?

Now that you know which suppliers have the best customer service, compare their current rates:

• Compare The Market Energy – Compare all suppliers with cashback
• Uswitch Energy Comparison – Often shows exclusive deals
• MoneySuperMarket Energy – Quick comparison tool

These are affiliate links - I may earn a small commission if you use them, at no extra cost to you. All analysis and recommendations in this article are independent and based solely on the data sources cited.