Amazon has secured permission for its Prime Air drones to fly further and across urban areas, opening the way for wider UK operations as access in Darlington expands from about 600 customers to around 8,000 households.

From Tuesday, those households will be able to receive eligible everyday items in under an hour. The service is included in Amazon Prime membership, with no additional delivery fee.

The Civil Aviation Authority has granted Amazon a Sail 4 operating authorisation and flightworthiness validation. Sail stands for Specific Assurance and Integrity Level. Amazon described the approval as the world’s first at level four from the UK regulator.

Previously, Prime Air operated under a different CAA authorisation covering flights in less densely populated areas. The new permission therefore changes where the drones can operate, laying a regulatory foundation for expansion beyond the current service.

The Darlington pilot began earlier this year, marking Prime Air’s first expansion outside the United States. During the limited launch, deliveries have been available to customers with a garden, yard or driveway. Parcels must weigh less than 5lb and fit into a large shoebox; eligible products are identified while customers shop and at checkout.

Theunis Scheepers, Amazon’s director for Prime Air in Europe, said securing approval had taken years of engineering work and a commitment to safety. “This is just the beginning for Prime Air in the UK,” he said.

Amazon’s all-electric MK30 drone uses machine-learning models to monitor its surroundings throughout each flight, recognising other aircraft, people, animals and physical obstacles. During its descent, its systems are designed to identify and avoid hazards such as washing lines and trampolines that would not appear on a satellite map. Amazon also says the drones are designed to be quieter than a typical delivery.

The authorisation broadens the scope for drone deliveries, but the immediate offer remains specific: small, lightweight purchases delivered to eligible Darlington households, rather than a nationwide service.