100Green British Gas (July 2026)
Overview
100Green is the better choice for customer service and offers a cheaper fixed deal, though British Gas has stronger smartphone apps and a cheaper variable tariff.
Based on the evidence reviewed, 100Green may suit households prioritising customer service and lower-priced fixed energy deals. British Gas could be a better fit for those who prefer managing their account via a smartphone app or want a cheaper standard variable tariff.
About 100Green and British Gas
Who are 100Green?
100Green started in 2001 as Green Energy UK and is an independent energy supplier based in Hertfordshire. It operates as a small, premium supplier focused entirely on green energy.
Who is British Gas?
British Gas traces its roots to the Gas Light and Coke Company, incorporated in 1812, and has been part of Centrica plc since 1997. Today, it is one of the UK's oldest and one of the UK's largest domestic energy suppliers.
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Tariffs and pricing
Across both suppliers, the lowest-priced deal available is 100Green's Exclusive Spring 100% Green 12M July 27 fixed tariff, costing £1,671 a year. By comparison, the cheapest overall option from British Gas is its Fix and Fall Jul28 v3 fixed tariff, which is priced at £1,703 a year.
While 100Green's lowest-priced fixed contract lasts for 12 months, it does not apply an exit fee if you switch away early. Conversely, the cheapest fixed option from British Gas requires a 24-month commitment and carries a £150 total exit fee.
For households seeking a variable tariff without a fixed term, British Gas provides the lower rate. Its Standard Variable tariff costs £1,805 a year, whereas 100Green's Sparkling SVT variable equivalent is priced at £1,976 a year.
100Green and British Gas: Tariff Options
100Green
100Green offers a small range of energy tariffs, including a standard variable option and fixed-term deals. It also has specialist tariffs for customers wanting strict environmental standards or time-of-use rates.
British Gas
British Gas provides a wide selection of energy tariffs. The range includes standard variable and fixed-term options, as well as specialist tariffs for electric vehicle owners, homes with heat pumps, and households with solar panels or battery storage.
Customer reviews
100Green holds a Trustpilot rating of 4.6 out of 5, compared to 4.4 out of 5 for British Gas. A significant proportion of 100Green's feedback is positive, with 74% of reviewers awarding it five stars. British Gas has a 65% five-star share, while 20% of its reviewers leave a one-star rating.
Trustpilot reviewers frequently mention 100Green's customer service staff, noting the ability to speak to a representative without long waits. Conversely, some customers report communication issues regarding account changes or installations. British Gas customers often note the professionalism of visiting engineers, though negative feedback highlights difficulties in reaching the correct department and communication challenges over the phone.
In the annual Which? energy survey, 100Green achieves an overall score of 72, compared to 59 for British Gas. Furthermore, 100Green received 4 out of 5 for overall customer service, whereas British Gas was awarded 2 out of 5.
Smartphone apps
British Gas may be the more suitable choice for households that prefer managing their energy via a smartphone. Its application is highly rated on both major platforms and records over a million installs on Google Play. In contrast, 100Green's iOS app does not currently display a rating, and its Android version scores poorly on Google Play.
The British Gas app receives 4.5 out of 5 on the App Store and 4.0 out of 5 on Google Play. Recent release notes indicate the supplier regularly updates its software, introducing features such as top-up progress tracking for prepayment customers.
100Green's Android app scores 1.2 out of 5, though this is based on a small number of reviews. Meanwhile, a recent sample of iOS feedback for British Gas indicates some users experience issues with smart meter data display and the layout of separate gas and electricity screens.
Service and support
100Green performs strongly on independent service metrics, ranking 1st in the latest Citizens Advice data with a score of 4.33 out of 5. British Gas ranks 13th in the same dataset, scoring 2.61 out of 5.
For telephone inquiries, 100Green answers calls in an average of 7 seconds, compared to 51 seconds for British Gas. Both suppliers respond to social media messages in an average of 55 seconds and maintain formal vulnerability commitments registered with Citizens Advice.
British Gas is faster at replying to emails, responding to 97.9% within two days, whereas 100Green replies to 90.9% in that timeframe. 100Green operates its general phone lines from 8am to 8pm on weekdays and 9am to 1pm on weekends. British Gas lines are open from 8am to 6pm on weekdays and 9am to 2pm on Saturdays, remaining closed on Sundays.
Complaints and performance
In the last three months of 2025, 100Green received 150 complaints for every 100,000 customers. British Gas received 1,158 complaints per 100,000 customers in the same period. This means British Gas had a much higher rate of complaints than 100Green.
Green Energy Comparison
100Green
Citizens Advice data from early 2026 shows 100Green has a 100% renewable electricity mix. It buys its electricity from independent UK renewable generators, such as wind, solar, and hydro plants. It also supplies 100% green gas made from biomethane, rather than relying on carbon offsetting. Its premium EKO tariff has an independent eco-label from EKOenergy to show it meets strict green rules and helps local wildlife.[1]
British Gas
Citizens Advice data from early 2026 shows the British Gas electricity mix is largely nuclear, with some fossil fuel and renewables. The company aims to help the UK reach zero carbon emissions by 2050. It supports green energy through its PeakSave scheme, which gives customers half-price electricity on Sundays to encourage them to use power when there is plenty of renewable energy on the grid. It also sells and installs green home technology, including smart meters, heat pumps, solar panels, home batteries, and electric vehicle chargers.[2]
Our verdict
| If you care most about | Choose |
|---|---|
| The lowest annual cost on our assumptions | 100Green |
| Overall customer service | 100Green |
| A well-rated mobile app | British Gas |
| A greener fuel mix | 100Green |
100Green is the better choice for customer service and offers a cheaper fixed deal, though British Gas has stronger smartphone apps and a cheaper variable tariff.
100Green may suit households prioritising customer service metrics and lower-priced fixed-term contracts. Its top-place finish in the Citizens Advice rankings and an average phone wait time of 7 seconds suggest it is a reliable option for telephone support.
Alternatively, British Gas could be a better option for customers who prefer digital account management, as its smartphone apps receive higher ratings than 100Green's. It also provides a cheaper standard variable tariff for those who prefer not to commit to a fixed contract.
- Ranks 1st for customer service with Citizens Advice
- Cheaper overall fixed tariff with no exit fees
- Fast average call answering times
- 100% renewable electricity mix
- More expensive standard variable tariff
- Poorly rated Android smartphone app
- Cheaper standard variable tariff
- Higher-rated smartphone apps for iOS and Android
- Faster email response times
- Slower average call wait times
- Lower overall customer satisfaction scores
Frequently asked questions
Which is better overall, 100Green or British Gas?
100Green performs better overall because it scores highly for customer service and offers a cheaper fixed tariff. British Gas is a better choice if you want a reliable smartphone app or a cheaper standard variable option.
Which supplier has the cheapest energy tariff?
100Green currently offers the cheapest deal overall with its 12-month fixed tariff, which costs £1,671 a year. However, if you want a variable tariff with no fixed term, British Gas offers the cheaper rate at £1,805 a year.
Do customers prefer 100Green or British Gas?
Customers generally prefer 100Green. It holds a 4.6 Trustpilot rating and scores 72 in the Which? energy survey. British Gas has a 4.4 Trustpilot rating and a lower Which? score of 59.
Which supplier has the better smartphone app?
British Gas has much stronger smartphone apps. Its app scores 4.5 on the App Store and 4.0 on Google Play. 100Green's Android app has a very low rating of 1.2, and it does not currently have a rating available for its iOS app.
Who is faster at answering the phone, 100Green or British Gas?
100Green is much faster at answering customer calls. According to Citizens Advice, it takes an average of 7 seconds to answer the phone, compared to 51 seconds for British Gas.
Should I choose 100Green or British Gas?
If you want excellent customer service and a cheap fixed deal with no exit fees, choose 100Green. If you prefer to manage your energy via an app or want a cheaper standard variable deal, British Gas is the better option.
Do 100Green and British Gas charge exit fees on their fixed tariffs?
100Green does not charge an exit fee on its cheapest 12-month fixed tariff, meaning you can leave at any time without a penalty. British Gas charges a £150 total exit fee on its cheapest 24-month fixed tariff.
Which supplier is better for green energy?
100Green is a specialist green supplier offering 100% renewable electricity and green gas. British Gas relies on a mix that includes nuclear and fossil fuels, though it does run schemes like PeakSave to encourage energy use when renewable power is high.
What changed this month
This month, British Gas's cheapest tariff term changed from a variable tariff to a 24-month fixed deal, 100Green's cheapest tariff term changed from a variable tariff to a 12-month fixed deal, and 100Green's cheapest fixed tariff term rose from 1 month to 12 months. There were 35 other data changes this month — see the full changelog below for details.
Data changes this month (49)
100Green
- Trustpilot reviews1,496 → 1,511
- iOS app rating1.1 → no longer available
- iOS app ratings count20 → no longer available
- iOS sampled reviews avg stars1 → no longer available
- iOS sampled negative reviews8 → 0
- Play Store rating1.2692307 → 1.2413793
- Play Store ratings count27 → 30
- Play Store days since last update121 → 15
- Play Store positive ratings %3.8 → 3.4
- Play Store negative ratings %92.3 → 93.1
- Play Store neutral ratings %3.8 → 3.4
- Play Store net-positive %-88.5 → -89.7
- Citizens Advice rank6 → 1
- Citizens Advice score3.62 → 4.33
- Complaints per 10,000 customers17.9 → 14.4
- Avg call centre wait time10 → 7
- Avg social media response timenow available (55)
- Emails responded within 2 days %96.9 → 90.9
- Cheapest variable tariff£1,914.44 → £1,975.79
- Cheapest fixed tariff£1,921.16 → £1,671.16
- Cheapest tariff£1,914.44 → £1,671.16
- Cheapest tariff termvariable → 12 months
- Cheapest fixed tariff term1 month → 12 months
- Shortest fixed term1 month → 12 months
- Longest fixed term1 month → 12 months
British Gas
- Trustpilot reviews342,242 → 345,969
- iOS app days since last update1,096 → 9
- iOS app updates in last 90 days0 → 3
- iOS sampled reviews avg stars1.67 → 2
- iOS sampled negative reviews3 → 2
- Play Store rating3.99223 → 4.0481653
- Play Store ratings count12,839 → 13,077
- Play Store days since last update23 → 14
- Play Store positive ratings %74.5 → 76.2
- Play Store negative ratings %21.3 → 20
- Play Store neutral ratings %4.2 → 3.7
- Play Store net-positive %53.2 → 56.2
- Citizens Advice rank14 → 13
- Citizens Advice score2.28 → 2.61
- Complaints per 10,000 customers73.5 → 68.7
- Avg call centre wait time91 → 51
- Avg social media response timenow available (55)
- Emails responded within 2 days %97.1 → 97.9
- Cheapest variable tariff£1,584.14 → £1,804.81
- Cheapest fixed tariff£1,675.23 → £1,702.64
- Cheapest tariff£1,584.14 → £1,702.64
- Cheapest tariff exit fee£0 → £150
- Cheapest tariff termvariable → 24 months
- Shortest fixed term15 months → 14 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.