NHS NUMBER
Change history 2.3.1
Description Where Used Attribute

Format/length: n10
HES item: NEWNHSNO
National Codes:
Default Codes:

Notes:
References:
UK Government Data Standards Catalogue (GDSC), Version 2.0, Agreed 01.01.02. GDSC:
http://www.govtalk.gov.uk/gdsc/html/default.htm

NHS NUMBER is the same as attribute NHS NUMBER.

It is mandatory to record the NHS NUMBER for each PATIENT. The exception to this rule is A&E care. The NHS NUMBER, the primary identifier of a PERSON, is a unique identifier for the PATIENT.

The NHS NUMBER is 10 numeric digits in length. The tenth digit is a check digit used to confirm its validity. The check digit is validated using the Modulus 11 algorithm and the use of this algorithm is mandatory. There are 5 steps in the validation of the check digit:

Step 1 Multiply each of the first nine digits by a weighting factor as follows:

Digit Position
(starting from the left)		 Factor
1 10
2 9
3 8
4 7
5 6
6 5
7 4
8 3
9 2
Step 2 Add the results of each multiplication together.

Step 3 Divide the total by 11 and establish the remainder.

Step 4 Subtract the remainder from 11 to give the check digit.
If the result is 11 then a check digit of 0 is used.
If the result is 10 then the NHS NUMBER is invalid and not used.

Step 5 Check the remainder matches the check digit. If it does not, the NHS NUMBER is invalid.

References:
NHS Strategic Tracing Service: http://nww.nhsia.nhs.uk/nsts/pages/faq.asp

UK Government Data Standards Catalogue

Data Element NHS Number
Is Part Of
Person Identifiers
Has Parts  
Version 2.0
Status Release
Previous Versions  
Later Versions  
Date Agreed 1 January 2002

Meta Data Value
Name NHS Number
Description A number used to identify a person uniquely within the NHS in England and Wales.
Business Format 10 numeric
Element Type Data Item
Validation
The tenth digit of the NHS Number is a check digit used to confirm its validity. The check digit is validated using the Modulus 11 algorithm and the use of this algorithm is mandatory. There are 5 steps in the validation of the check digit:
Step 1 Multiply each of the first nine digits by a weighting factor as follows:
Digit Position
(Starting from the left)		 Factor
1 10
2 9
3 8
4 7
5 6
6 5
7 4
8 3
9 2

Step 2 Add the results of each multiplication together.


Step 3 Divide the total by 11 and establish the remainder.


Step 4 Subtract the remainder from 11 to give the check digit. If the result is 11 then a check digit of 0 is used. If the result is 10 then the NHS NUMBER is invalid and not used.


Step 5 Check the remainder matches the check digit. If it does not, the NHS NUMBER is invalid.
Value  
Default Value  
Owner Department of Health
Based On Department of Health
Verification  
Comment
 

This data element is also known by these names:

Context Alias
plural NHS NUMBERS