The NHS app was knocked out of action for all 10 million of its users after an internet outage hit websites and tech tools across the world.
The Covid pass service was left inaccessible after a web infrastructure company’s service went offline with a fault just after 5pm on Thursday.
Banking apps and websites including HSBC, Barclays and Lloyds all crashed in the outage that hit dozens of sites.
Other websites reporting outages and unable to load included Airbnb, Waitrose and Tesco Bank. The Playstation Network was also failing to load for gamers.
Social media users complained they were unable to access banking services online to make payments.
The problem was traced to Akamai, the world’s largest content delivery network. The network is designed to stop websites overloading with traffic and to avoid bottlenecks on the internet.
A post on Akamai’s site said: “We are aware of an emerging issue with the Edge DNS service. We are actively investigating the issue.”
NHS Digital said: “We are aware of issues with services such NHS 111 Online, the NHS App and services on the NHS website. These are part of the wider Akamai DNS issues impacting many organisations globally.”
The NHS Covid-19 contact-tracing app was not impacted.
The outage lasted just over an hour, before websites running on Akamai began coming back online.
An Akamai spokesperson said: “We have implemented a fix for this issue, and based on current observations, the service is resuming normal operations. We will continue to monitor to ensure that the impact has been fully mitigated.
“We are continuing to monitor the situation and can confirm this was not a result of a cyber attack on the Akamai platform.”
In a blog earlier this year, the NHS said it had started using Akamai’s content delivery network as a kind of “‘waiting room’ technology, which people are more familiar seeing when booking tickets for popular events such as stadium concerts”.
The outage follows a global fault with Fastly, another content delivery network provider, which went down in June taking dozens of UK government websites offline, including the gov.uk domain. Etsy, Hulu, HBO Max, PayPal, Amazon, Twitch and Twitter also reported problems.
Infrastructure providers such as Akamai and Fastly provide an increasingly interwoven backbone of the web, providing support, internet filtering and cyber security services to thousands of websites.
These tools can prevent sudden spikes in traffic from knocking out websites, or block coordinated cyber attacks designed to overload services.
However, they also mean thousands of websites can be impacted if they have any faults of their own, cutting off key services such as with the NHS app.
An estimate from Imperial College and Opinium put the cost of web outages at £12bn per year for the UK.