100Green British Gas (August 2026)
Overview
100Green leads on customer service and fixed prices, but British Gas offers much better apps and a cheaper variable tariff.
100Green scores higher across most independent customer service and review metrics, which may suit households prioritising fast phone support. Conversely, British Gas provides higher-rated smartphone apps and a cheaper variable tariff.
About 100Green and British Gas
Who are 100Green?
Set up in 2001 as Green Energy UK, 100Green is an independent, privately owned company based in Hertfordshire. It operates as one of the UK's smaller domestic energy suppliers. The company focuses on phone-based customer service with real staff rather than chatbots, and it holds Which? Recommended Provider status for 2026.
Who is British Gas?
Tracing its history back to 1812, British Gas is one of the UK's oldest and most recognised energy suppliers. The UK government privatised the business in 1986, and it is now owned by Centrica plc. Today, it is one of the UK's largest domestic energy suppliers.
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Tariffs and pricing
The cheapest available tariffs from 100Green and British Gas are closely matched, with a difference of just £4 a year based on our assumptions. 100Green's lowest-priced option is a 12-month fixed tariff, Exclusive Spring 100% Green 12M August 27, priced at £1,749 a year with no exit fees. In contrast, British Gas's cheapest overall deal is a variable tariff, Cap Tracker Plus Sep27 v1, costing £1,745 a year with a 0-month term and a £50 exit fee.
For households seeking price certainty, 100Green provides the cheaper fixed option. It costs £85 a year less than British Gas's 24-month fixed deal, which includes a £150 exit fee. However, British Gas offers the cheaper variable tariff at £1,745 a year, compared to £1,976 a year for 100Green's variable equivalent.
Tariff Options
100Green
100Green offers standard variable and fixed tariffs for household customers. It also offers specialist smart tariffs for homes that can shift their energy use or generate their own renewable power.
British Gas
British Gas offers standard variable, fixed, and tracker tariffs for domestic customers. It also offers several smart and specialist tariffs for electric vehicle owners, homes with battery storage, and those with solar panels or heat pumps.
Customer reviews
100Green holds a Trustpilot rating of 4.6 from a low volume of reviews, while British Gas scores 4.4 from a significantly larger sample of over 350,000. Five-star ratings account for 74% of 100Green's feedback, compared to 65% for British Gas. One-star reviews make up 20% of the British Gas total, whereas 7% of 100Green reviews fall into this lowest tier. Both suppliers typically reply to negative feedback within 24 hours.
Reviewers frequently mention 100Green's helpful staff and quick response times, highlighting the team's efficiency in resolving price and service queries. British Gas customers regularly note polite staff and efficient repairs, although some report issues with billing mistakes and payment processes.
In the annual Which? survey, 100Green achieves an overall score of 72 out of 100, compared to 59 out of 100 for British Gas. 100Green receives 4 out of 5 for overall customer service, while British Gas receives 2 out of 5. Conversely, British Gas records 8 out of 10 for help for those who need it, ahead of 100Green's 4 out of 10. Both suppliers perform poorly in the switching category, with 100Green scoring 1 out of 5 and British Gas scoring 0 out of 5.
App quality and features
British Gas provides a more established option for customers preferring to manage their accounts via a smartphone. Its iOS app scores 4.5 from 13,000 ratings, whereas 100Green scores 1.1 from a very small sample. A similar gap exists on the Google Play Store, where British Gas scores 4.1 against 1.2 for 100Green. The British Gas Android app records over a million installs and has been updated very recently.
A recent sample of iOS reviews for 100Green indicates a basic interface, with users reporting difficulties adjusting settings or viewing bills. Meanwhile, a small sample of British Gas users note the app can feel clunky, expressing frustration over separate logins for gas and electricity. The latest British Gas update introduces a feature allowing prepayment users to check their emergency credit status directly in the app.
Service and support
100Green ranks 1st in the Citizens Advice ratings, achieving an overall score of 4.33 out of 5. British Gas places 13th with a score of 2.61 out of 5. Call wait times average 7 seconds for 100Green, compared to 51 seconds for British Gas.
British Gas is slightly faster at handling email queries, responding to 97.9% within two days, compared to 90.9% for 100Green. Both suppliers maintain formal vulnerability commitments registered with Citizens Advice.
100Green operates its phone lines from 8am to 8pm on weekdays and from 9am to 1pm on weekends. British Gas is available from 8am to 6pm on weekdays and 9am to 2pm on Saturdays, remaining closed on Sundays. Both suppliers accept Direct Debit, cash, cheques, and prepayment at a brand level.
Complaints and performance
In Q4 2025, 100Green received 150 complaints per 100,000 customers. This is much lower than British Gas, which received 1,158 complaints per 100,000 customers in the same period.
Green Energy Comparison
100Green
Based on Citizens Advice data for January to March 2026, 100Green supplies a 100% renewable electricity mix. The company buys its electricity directly from small UK renewable generators, such as wind, solar, hydro, and biomass sites, rather than just buying green certificates. It also supplies 100% green gas made from organic waste through anaerobic digestion, and it does not use carbon offsetting.[1]
British Gas
Based on Citizens Advice data for January to March 2026, the British Gas electricity mix is largely nuclear, with some fossil fuel and renewables. The company offers some green tariffs where the electricity is backed by Renewable Energy Guarantees of Origin (REGO) certificates. Its parent company, Centrica, is investing in training academies to teach workers how to install heat pumps and solar panels, and the supplier aims to help the UK reach zero carbon emissions by 2050.[2]
Our verdict
| If you care most about | Choose |
|---|---|
| The lowest annual cost on our assumptions | Either |
| Overall customer service | 100Green |
| A well-rated mobile app | British Gas |
| A greener fuel mix | 100Green |
100Green leads on customer service and fixed prices, but British Gas offers much better apps and a cheaper variable tariff.
100Green scores higher across the independent customer service and review metrics analysed, which may suit households prioritising fast phone support. Conversely, British Gas provides a more highly rated smartphone app experience and a cheaper variable tariff.
British Gas may suit customers who prefer managing their energy via a smartphone app or those seeking a cheaper variable deal. Alternatively, 100Green may be more appropriate for households that prioritise fast phone support and higher independent service scores.
- Ranks 1st in Citizens Advice data
- Average call wait time of 7 seconds
- Cheaper fixed tariff option
- Higher Which? and Trustpilot scores
- Low smartphone app ratings
- Variable tariff costs more
- Higher-rated iOS and Android apps
- Cheaper variable tariff
- Responds to 97.9% of emails within two days
- Ranks 13th with Citizens Advice
- One in five Trustpilot reviews is one-star
- Higher fixed tariff prices
Frequently asked questions
Which supplier is better overall, 100Green or British Gas?
100Green ranks higher for customer service and offers a cheaper fixed tariff, making it a strong choice for those who value fast phone support. However, British Gas is the better choice if you want highly rated smartphone apps or a cheaper variable tariff.
Do 100Green and British Gas charge exit fees?
100Green's cheapest fixed tariff does not charge an exit fee. British Gas charges a £50 exit fee on its cheapest variable option and £150 on its cheapest fixed deal.
Who gets better reviews, 100Green or British Gas?
100Green performs better across review platforms. It holds a Trustpilot rating of 4.6 compared to 4.4 for British Gas, and scores 72 out of 100 in the annual Which? survey, while British Gas scores 59.
Are the 100Green and British Gas apps easy to use?
British Gas offers a much better app experience, scoring 4.5 on the App Store and 4.1 on the Google Play Store. 100Green's apps are rated very poorly, scoring just 1.1 on iOS and 1.2 on Android.
How long does it take to get through to 100Green and British Gas on the phone?
100Green answers phone calls very quickly, with an average wait time of just 7 seconds according to Citizens Advice. British Gas takes an average of 51 seconds to answer.
Should I choose 100Green or British Gas?
Choose 100Green if you want excellent customer service, fast call answering, and a cheaper fixed tariff. Choose British Gas if you prefer managing your account via a highly rated mobile app or want a cheaper variable tariff.
What are the opening hours for 100Green and British Gas?
100Green is open from 8am to 8pm on weekdays and 9am to 1pm on weekends. British Gas is open from 8am to 6pm on weekdays and 9am to 2pm on Saturdays, but is closed on Sundays.
Which supplier offers the cheaper fixed tariff?
100Green currently offers the cheaper fixed tariff. Its 12-month fixed deal costs £1,749 a year, which is £85 cheaper than the 24-month fixed deal from British Gas.
How do 100Green and British Gas perform in the Which? survey?
100Green scores 72 out of 100 in the Which? survey, achieving 4 out of 5 for overall customer service. British Gas scores 59 out of 100, achieving 2 out of 5 for overall customer service.
What changed this month
This month, 100Green's play store days since last update rose from 15 to 37, 100Green's iOS app updates in last 90 days rose from 0 to 3, and British Gas's iOS app updates in last 90 days fell from 3 to 0. There were 21 other data changes this month — see the full changelog below for details.
Data changes this month (31)
100Green
- Trustpilot reviews1,511 → 1,539
- iOS app ratingnow available (1.1)
- iOS app ratings countnow available (21)
- iOS app days since last updatenow available (61)
- iOS app updates in last 90 days0 → 3
- iOS sampled reviews avg starsnow available (1.33)
- iOS sampled negative reviews0 → 3
- Play Store days since last update15 → 37
- Avg social media response time55 → no longer available
- Cheapest fixed tariff£1,671.16 → £1,748.8
- Cheapest tariff£1,671.16 → £1,748.8
British Gas
- Trustpilot reviews345,969 → 350,018
- iOS app days since last update9 → 16
- iOS app updates in last 90 days3 → 0
- iOS sampled negative reviews2 → 3
- Play Store rating4.0481653 → 4.0881915
- Play Store ratings count13,077 → 13,409
- Play Store days since last update14 → 9
- Play Store positive ratings %76.2 → 77.4
- Play Store negative ratings %20 → 19.1
- Play Store neutral ratings %3.7 → 3.4
- Play Store net-positive %56.2 → 58.3
- Avg social media response time55 → no longer available
- Cheapest variable tariff£1,804.81 → £1,744.71
- Cheapest fixed tariff£1,702.64 → £1,833.95
- Cheapest tariff£1,702.64 → £1,744.71
- Cheapest tariff exit fee£150 → £50
- Cheapest tariff term24 months → 0 months
- Fixed tariffs available2 → 1
- Variable tariffs available1 → 2
- Shortest fixed term14 months → 24 months
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Written by
Rob Gibbs
Hi, I'm Rob, and I run Energy-Review.co.uk. I initially started this project in 2018 when I was looking to switch energy suppliers and found there wasn't a website that provided simple, data-backed reviews on all the suppliers available. Since then, I have spent a lot of time (too much, some may say!) looking at all publicly available data about each supplier and writing reviews using this information. These reviews are updated as regularly as possible, and any data is backed up by a source where necessary. I have also started writing guides on various energy-related topics, which hopefully you will find useful. If you find any issues, please use our contact form to let us know.