100Green British Gas (September 2026)
Overview
British Gas may suit households prioritising lower estimated costs and a stronger app, while 100Green stands out for customer service and green energy.
British Gas wins this comparison by offering cheaper tariffs and higher-rated mobile apps. 100Green may suit households that prioritise highly rated customer service and a 100% renewable energy mix.
About 100Green and British Gas
Who are 100Green?
100Green is an independent energy supplier based in Hertfordshire. Set up in 2001 as Green Energy UK, it focuses on environmentally conscious households and offers an alternative to the biggest energy companies. The supplier makes a point of its customer service by using real people to answer calls rather than automated menus, and some fixed tariffs may include exit fees.
Products & services
Awards & recognition
Who is British Gas?
British Gas is one of the UK's oldest energy brands and remains one of the biggest domestic suppliers in the country. Owned by Centrica, it provides gas and electricity to millions of homes. It offers a wide range of products alongside energy supply, such as boiler cover, heating repairs, and Hive smart home devices, as well as running reward schemes to help lower bills.
Products & services
Awards & recognition
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Tariffs and pricing
British Gas provides the cheaper overall deal in this comparison. Its lowest-priced option is the Cap Tracker Plus Sep27 v1, a variable tariff estimated at £1,551 a year. This works out to £167 a year—or about £14 a month—less than 100Green's cheapest equivalent. The British Gas variable deal does not have a fixed term, though it carries a £50 exit fee.
For 100Green, the most affordable tariff is the Exclusive Spring 100% Green 12M September 27. This 12-month fixed deal costs £1,717 a year and comes with no exit fees.
Households seeking price certainty will find that British Gas also offers the cheaper fixed deal. Its Fix and Boiler Bonus v14 tariff costs £1,649 a year over a 21-month term, but it includes a £200 exit fee. By comparison, 100Green's lowest-priced variable option, the Sparkling SVT, is estimated at £1,762 a year.
| Metric | 100Green | British Gas |
|---|---|---|
| Cheapest overall tariff exit fee | £0 | £50 |
| Cheapest fixed tariff exit fee | £0 | £200 |
Tariff Options
100Green
100Green offers a focused range of domestic tariffs, including standard variable and fixed-term options. It also provides specialist smart time-of-use tariffs for customers who want to manage their energy use more closely.
British Gas
British Gas offers domestic tariffs covering standard variable, tracker, and fixed-term options. It also has specialist smart tariffs for homes with electric vehicles, heat pumps, battery storage, and solar panels.
Customer reviews
Both suppliers hold positive ratings on Trustpilot, with 100Green scoring slightly higher overall, albeit from a smaller sample size. 100Green achieves 4.6 out of 5 across 1,559 reviews, and 74% of these are five stars. British Gas scores 4.5 out of 5 from a much larger pool of over 353,000 reviews, with 66% awarding five stars. However, 20% of the British Gas feedback is one-star, compared to 8% for 100Green.
Reviewers frequently note that 100Green staff answer calls promptly and handle the switching process efficiently, though a small number mention occasional billing discrepancies or slow interactions. British Gas customers regularly highlight polite engineers arriving on time, while critical reviews point to long waiting times, unhelpful support, and missed appointments.
In the annual Which? survey, 100Green achieves an overall score of 72, ahead of British Gas at 59. 100Green receives 4 out of 5 for overall customer service and 12 out of 15 for complaints handling. In contrast, British Gas scores 2 out of 5 for service and 5 out of 15 for complaints. However, British Gas performs better in the 'help for those who need it' category, scoring 8 out of 10 compared to 100Green's 4 out of 10.
App quality and features
British Gas provides higher-rated mobile apps than 100Green. The British Gas iOS app scores 4.5 out of 5 from 14,000 ratings, and the Google Play version scores 4.2 from over 13,000 ratings. A recent sample of its iOS reviews averages 1.7 stars, with some users reporting bugs. Both suppliers have updated their software recently, with the latest British Gas release adding emergency credit tracking for prepayment users.
The 100Green apps receive lower scores, though these are based on small sample sizes. Its iOS app holds 1.1 out of 5 from 21 ratings, while the Google Play edition scores 1.2 from 32 ratings. A recent sample of iOS reviews indicates that some 100Green users find the app basic, difficult to navigate, and lacking in accessibility features.
Service and support
Average wait: 7 sec
Hours: Weekdays 8am–8pm, open Saturday and Sunday 9am–1pm
Average wait: 51 sec
Hours: Weekdays 8am–6pm, open Saturday 9am–2pm, closed Sunday
Replies: 91% within 2 days
Hours: 24/7
Replies: 98% within 2 days
Hours: 24/7
Average response: ~1 min
Hours: Business hrs
Average response: ~1 min
Hours: Business hrs
100Green scores higher across the independent service metrics evaluated in this comparison. It ranks 1st in the Citizens Advice ratings with an overall score of 4.33 out of 5, whereas British Gas ranks 13th with a score of 2.61.
For phone support, 100Green answers calls in an average of 7 seconds, compared to 51 seconds for British Gas. Both suppliers take an average of 55 seconds to respond to social media messages. When handling emails, British Gas replies to 97.9% of inquiries within two days, while 100Green manages 90.9% in the same timeframe.
Both companies maintain formal vulnerability commitments registered with Citizens Advice. 100Green operates its phone lines from 8am to 8pm on weekdays and 9am to 1pm on weekends. British Gas is available from 8am to 6pm on weekdays and 9am to 2pm on Saturdays, and is closed on Sundays.
| Metric | 100Green | British Gas |
|---|---|---|
| Average social media response time | 55 seconds | 55 seconds |
Complaints and performance
Complaint figures are shown with each supplier’s reporting period. No winner is declared when periods differ or one figure is missing.
Green Energy Comparison
100Green
100Green supplies a 100% renewable electricity mix. It also supplies 100% green gas made from biomethane, which is produced from farm and food waste rather than fossil fuels. This means it supplies actual green gas rather than relying on carbon offsetting to meet its environmental claims.[1]
British Gas
The British Gas electricity mix is largely nuclear, with some fossil fuels and renewables. Its mainstream electricity fuel mix is not wholly renewable. To help customers lower their carbon footprint, it offers green upgrades such as heat pumps, solar panels, and electric vehicle chargers. It also encourages greener energy habits through its PeakSave scheme, which rewards customers for shifting their electricity use to off-peak times when more renewable power is available on the grid. The company has set a target to reach net zero carbon emissions by 2050.[2][3]
Our verdict
| If you care most about | Choose |
|---|---|
| The lowest annual cost on our assumptions | British Gas |
| Overall customer service | 100Green |
| A well-rated mobile app | British Gas |
| A greener fuel mix | 100Green |
British Gas may suit households prioritising lower estimated costs and a stronger app, while 100Green stands out for customer service and green energy.
British Gas is the winner of this comparison, primarily because it offers cheaper tariffs and higher-rated mobile apps. Its lowest-priced overall deal costs £167 less a year than the cheapest option from 100Green, which may appeal to households focused on reducing their energy bills.
100Green may suit households that prioritise customer service and environmental credentials. It ranks 1st in the Citizens Advice ratings and answers calls faster than British Gas. It also provides a 100% renewable energy mix, which could appeal to those looking for a greener tariff.
- Ranks 1st in the Citizens Advice ratings
- Answers calls in an average of 7 seconds
- Supplies a 100% renewable electricity mix
- Higher estimated costs across fixed and variable tariffs
- Low ratings for its mobile apps on iOS and Android
- Cheaper overall, fixed, and variable tariffs
- Higher-rated apps on iOS and Android
- Replies to 97.9% of customer emails within two days
- Lower Citizens Advice and Which? scores
- Slower average call centre wait times
- 20% of Trustpilot reviews are one-star
Frequently asked questions
Which is better overall, 100Green or British Gas?
British Gas wins overall in this comparison because it offers significantly cheaper tariffs and highly rated mobile apps. 100Green is a strong alternative if you prioritise customer service, as it ranks first in the Citizens Advice ratings.
Which supplier has the cheaper energy tariffs?
British Gas offers the cheaper tariffs. Its lowest-priced variable deal costs £167 less a year than the cheapest fixed tariff from 100Green. British Gas also provides a cheaper fixed deal than 100Green.
Do customers prefer 100Green or British Gas?
Both suppliers have positive Trustpilot ratings, but 100Green scores higher in independent surveys. 100Green achieves a Which? score of 72 and receives 4 out of 5 for overall customer service, whereas British Gas scores 59 and receives 2 out of 5 for service.
Are the 100Green and British Gas apps easy to use?
The British Gas apps are highly rated, scoring 4.5 out of 5 on the App Store and 4.2 on Google Play. In contrast, the 100Green apps receive very low ratings of 1.1 and 1.2 on these platforms, with users finding them basic and hard to use, though these scores are based on a very small number of reviews.
Which supplier answers the phone faster?
100Green answers customer calls much faster. It takes an average of just 7 seconds to connect to a 100Green agent, compared to 51 seconds for British Gas. Both suppliers respond to social media messages in under a minute.
Should I switch to 100Green or British Gas?
If you want to keep your energy bills as low as possible and manage your account through a reliable app, British Gas is the better option. If you are willing to pay more for top-tier customer support and a 100% renewable energy mix, 100Green is an excellent choice.
Do 100Green and British Gas charge exit fees?
100Green does not charge exit fees on its fixed tariffs, allowing you to leave without penalty. British Gas charges a £50 exit fee on its cheapest variable tariff and a £200 exit fee on its lowest-priced fixed deal.
What are the opening hours for 100Green and British Gas?
100Green phone lines are 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.
What do customers say about British Gas on Trustpilot?
British Gas receives a positive 4.5 out of 5 overall on Trustpilot, with 66% of reviewers giving it five stars for polite and efficient engineers. That said, 20% of its reviews are one-star, with some customers reporting long waiting times and unhelpful communication.
Do 100Green and British Gas update their mobile apps regularly?
Yes, both suppliers maintain their apps actively. The British Gas and 100Green apps have both received three updates in the last 90 days, ensuring they are kept up to date with bug fixes and new features.
What changed this month
This month, British Gas's fixed tariffs available rose from 1 to 3, British Gas's iOS sampled negative reviews rose from 0 to 3, and British Gas's play store days since last update rose from 10 to 18. There were 34 other data changes this month — see the full changelog below for details.
Data changes this month (44)
100Green
- Trustpilot reviews1,539 → 1,559
- Trustpilot 4-star %12 → 11
- Trustpilot 1-star %7 → 8
- Trustpilot positive reviews %86 → 85
- Trustpilot negative reviews %10 → 11
- Trustpilot net-positive %76 → 74
- iOS app days since last update38 → 25
- Play Store rating1.2413793 → 1.2258065
- Play Store ratings count30 → 32
- Play Store days since last update38 → 26
- Play Store positive ratings %3.4 → 3.2
- Play Store negative ratings %93.1 → 93.5
- Play Store neutral ratings %3.4 → 3.2
- Play Store net-positive %-89.7 → -90.3
- Avg social media response timenow available (55)
- Cheapest variable tariff£1,975.79 → £1,761.9
- Cheapest fixed tariff£1,748.8 → £1,717.28
- Cheapest tariff£1,748.8 → £1,717.28
British Gas
- Trustpilot rating4.4 → 4.5
- Trustpilot reviews350,018 → 353,681
- Trustpilot 5-star %65 → 66
- Trustpilot 3-star %4 → 3
- Trustpilot positive reviews %73 → 74
- Trustpilot neutral reviews %4 → 3
- Trustpilot net-positive %50 → 51
- iOS app ratings count13,000 → 14,000
- iOS app days since last update9 → 15
- iOS sampled reviews avg starsnow available (1.67)
- iOS sampled negative reviews0 → 3
- Play Store rating4.0881915 → 4.1812863
- Play Store ratings count13,409 → 13,701
- Play Store days since last update10 → 18
- Play Store positive ratings %77.4 → 80.1
- Play Store negative ratings %19.1 → 16.4
- Play Store net-positive %58.3 → 63.7
- Avg social media response timenow available (55)
- Cheapest variable tariff£1,744.71 → £1,550.78
- Cheapest fixed tariff£1,833.95 → £1,649.29
- Cheapest tariff£1,744.71 → £1,550.78
- Cheapest fixed tariff exit fee£150 → £200
- Cheapest fixed tariff term24 months → 21 months
- Tariff count3 → 5
- Fixed tariffs available1 → 3
- Shortest fixed term24 months → 21 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.