This feature, which details the dose of vaccine a person receives, is needed by people wishing to travel abroad as proof that they have been vaccinated against the virus.
Consumers reported seeing an error message on the NHS smartphone app on Wednesday afternoon, saying the high demand was “restricting access to the service”.
Responding to the issue, NHS Digital said in a statement: “There are currently issues with access to the Quid Pass on the NHS app and website. We are investigating the matter and will contact you as soon as possible. Will date
Vacationers complained about the closure on Twitter, with one person claiming he missed the flight because of the problem. Others who are due to fly this week described the situation as “stressful”.