Table 2.

NHS Digital deterministic matching steps

Match rank	NHS number	Date of birth	Sex	Postcode*
1	Exact	Exact	Exact	Exact
2	Exact	Exact	Exact
3	Exact	Partial	Exact	Exact
4	Exact	Partial	Exact
5	Exact			Exact
6		Exact	Exact	Exact	Where NHS number does not contradict the match and DOB is not 1 January and the postcode is in the ‘ignore’ list.†
7		Exact	Exact	Exact	Where NHS number does not contradict the match and DOB is not 1 January.
8	Exact

*Current or most recently recorded postcode.

†The ‘ignore’ list includes postcodes for communal establishments such as hospitals, care homes, prisons and boarding schools.

DOB, date of birth; NHS, National Health Service.