The Isles of Scilly fuel duty rebate has been extended to 2023.
The islands will continue to receive a 5p per litre reduction in fuel costs for a further six years.
The measure was introduced in Scilly and the Western Isles of Scotland in 2012 in a bid to help remote communities.
Transport costs and buying in smaller quantities means islands can miss out on bulk purchase discounts.
The EU approved the rollout of the fuel rebate to 17 areas of England and Wales in April 2015.