In a blog post, Kelsey wrote: “We will require all NHS providers funded by NHS England to use the NHS number as their primary identifier so that all data can be linked and patients identified, with accuracy. From April 2014, this will be a contractual obligation for providers."
The NHS Number mandate was a key component of The Power of Information document published by the Department for Health, which set the policy of the NHS number being taken up by 2015.
Under the move, all patient data in publicly-funded health and social care will be identified by the NHS number as the primary identifier at the point of care by 2015.
NHS numbers will be used to connect records across the whole system as the NHS move between services to enable a joined-up care service, said the document.
Jon Lindberg, associate director of healthcare at IT trade body Intellect, said: “Industry is aware of the requirement coming in to effect from 2015 in the strategy and now the contractual obligations for providers by 2014.
"The key challenge is for providers to work out how they can achieve that together with their systems suppliers, if they haven’t already.”
The news follows a new £1.2bn framework from the Department of Health for a GP Systems of Choice, a scheme that offers central funding for GP clinical IT systems.