UK Government Data Standards Catalogue

Metadata Value
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

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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
XML Schema
View whole schema document Citizen Identification Types as XML
View definition DigNHSnumberType as HTML
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
DefaultValue
Owner Department of Health
Based On Department of Health
Verification
Comment