It is mandatory to record the NHS NUMBER. There are exceptions, such as emergency care, sexual health and major incidents, as defined in existing national policies.
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:
(starting from the left) Factor:
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.
This attribute is also known by these names: