100Green Review (August 2026)
Overview
100Green offers highly rated customer service and fast call response times, though its smartphone apps receive very poor feedback.
Who are 100Green?
Founded in 2001, 100Green is an independent energy supplier based in Hertfordshire. It is one of the UK's oldest green energy suppliers outside the traditional big firms, supplying gas and electricity to households across Great Britain.
What sets 100Green apart is its green gas offering. It is the only UK energy supplier to give domestic customers 100% green gas alongside 100% renewable electricity. Because it costs more to buy fully renewable energy, 100Green holds a special exemption from the Ofgem price cap.
Products & services
- Gas and electricity
- 100% renewable electricity and 100% green gas
- Fixed tariffs
- 12-month fixed-rate deals
- Standard variable tariff
- flexible rates with no fixed term
- Smart tariffs
- time-of-use rates for smart meter customers
Awards & recognition
- ✓Which? Recommended Provider — 2026
- ✓Best Small Supplier (Uswitch Energy Awards) — 2025
Use our referral link, and we'll both get £50 credit once your switch is complete.
Existing customer? Find out how you can benefit too. T&Cs apply (only one switching offer per household)
Prices
These are the tariffs we have pricing for — the supplier may offer others.
The cheapest available tariff from 100Green is a 12-month fixed deal named Exclusive Spring 100% Green 12M August 27, priced at £1,749 a year. This option carries no exit fees.
Households can also opt for the Sparkling SVT variable tariff, which costs £1,976 annually. It has no fixed term and similarly applies a £0 exit fee if you decide to switch.
Tariff details
This supplier's full tariff range
100Green offers a range of standard variable and fixed-rate tariffs, alongside specialist options for eco-conscious households and those with smart meters.
Customer reviews
100Green holds a Trustpilot rating of 4.6 based on over 1,500 reviews. The feedback is predominantly positive, with 74% of users awarding five stars and 7% leaving a one-star score.
Reviewers frequently highlight the supplier's customer service, noting that staff are knowledgeable and professional. Fast response times across phone and email channels are regularly mentioned in positive comments.
During the annual Which? energy survey, 100Green achieved a total score of 72. It received 4 out of 5 for overall customer service and 12 out of 15 for complaints handling, though its switching process scored 1 out of 5, alongside a 3 out of 5 rating for value for money.
Apps
Feedback for 100Green's smartphone apps is notably low. The iOS version holds a score of 1.1 from 21 ratings, and the Android app is rated 1.2 out of 5 based on 30 reviews on the Google Play Store.
A sample of iOS reviews indicates that users find the interface basic and difficult to navigate. Common complaints include connection issues, the inability to adjust payment settings within the software, and a requirement to download bills locally to view them.
The supplier does actively maintain its digital tools. The iOS app received three updates in the last 90 days, while the Android version was recently refreshed with a new design intended to simplify navigation.
Service and support
100Green ranks first in the Citizens Advice ratings with an overall score of 4.33 out of 5. Data shows the supplier answers phone calls in an average of 7 seconds and responds to 90.9% of emails within two days.
The company records 14.4 complaints per 10,000 customers. It has registered formal vulnerability commitments with Citizens Advice to assist households requiring additional support.
Phone support is available between 8am and 8pm on weekdays, and from 9am to 1pm on weekends. Accepted payment methods include Direct Debit, cash, cheque, and prepayment.
Complaints and performance
In Q4 2025, 100Green received 150 complaints for every 100,000 customers. The supplier resolved 18% of these complaints by the end of the next working day, and it resolved 100% within eight weeks.
Green energy
100Green supplies a 100% renewable electricity mix. According to its website, the supplier buys this electricity directly from independent UK generators using wind, solar, hydro, and anaerobic digestion.
For gas, 100Green supplies 100% green gas, also known as biomethane, which is made from farm and organic waste rather than fossil fuels. The supplier does not rely on carbon offsetting schemes to make its tariffs green.
The company also offers a premium tariff certified by EKOenergy, an international ecolabel. This certification ensures that the renewable energy is made in ways that protect local wildlife and habitats.
Verdict
100Green offers highly rated customer service and fast call response times, though its smartphone apps receive very poor feedback.
100Green may suit households prioritising traditional customer service over digital account management. The supplier's fast call response times and first-place ranking with Citizens Advice are reflected in positive Trustpilot feedback regarding its support staff.
Consumers who prefer managing their energy via a smartphone app might want to explore other providers, given the low ratings for 100Green's digital tools. Additionally, the supplier's switching process received a low score in the latest Which? survey.
Frequently asked questions
Is 100Green a good energy supplier?
100Green performs very well for customer service, ranking 1st with Citizens Advice and earning high marks on Trustpilot. However, its smartphone apps receive very poor ratings.
What is 100Green's cheapest tariff?
Its cheapest option is a 12-month fixed deal called Exclusive Spring 100% Green 12M August 27, which costs £1,749 a year.
Does 100Green charge exit fees?
No, both its cheapest fixed tariff and its variable tariff come with a £0 exit fee, meaning you can switch away without paying a penalty.
What do customers say about 100Green on Trustpilot?
100Green has a Trustpilot rating of 4.6. Customers frequently praise the helpful and knowledgeable staff, as well as the quick response times across phone and email.
Are 100Green's mobile apps any good?
Reviews suggest the apps are very basic and prone to connection issues. The iOS app is rated 1.1, and the Android app is rated 1.2 on the Google Play Store.
How long does it take 100Green to answer the phone?
According to Citizens Advice, 100Green answers customer calls in an average of just 7 seconds.
What are 100Green's opening hours?
The supplier's phone lines are open from 8am to 8pm on weekdays, and from 9am to 1pm on Saturday and Sunday.
Should I switch to 100Green?
100Green is a good choice if you want fast phone support and value highly rated customer service. However, if you rely on a slick app to manage your bills, you might be better off looking elsewhere.
Does 100Green supply green energy?
Yes, 100Green supplies 100% renewable electricity and 100% green gas to its domestic customers, avoiding the use of carbon offsetting schemes.
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 100Green's iOS sampled negative reviews rose from 0 to 3. There were 5 other data changes this month — see the full changelog below for details.
Data changes this month (11)
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
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.
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