NHS numbers as identifiers

Every patient has an NHS number which is unique to them, usually issued when they register with a GP.

On its own, an NHS number is unlikely to identify someone if the person viewing it has no access to other NHS systems. However, many health and care systems, such as the Personal Demographics Service (PDS), link the NHS number to other identifying details.

For that reason, the NHS number should be treated as an identifier whenever it is available to someone who also has access to a system which links it to identifiable information.