This is an HTML version of an attachment to the Freedom of Information request 'National Insurance number format'.

 
 
 
DWP Central Freedom of Information Team
Annex A 
 
e-mail: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx@xxx.xxx.  
gov.uk
 
 
 
 
 
Our Ref: IR 782
 
 

 30.10.2013
Annex A 
 
 
 
 
 
 
 
Dear Mr Hilton,  
 
Further to your Freedom of Information (VTR 4543) request received on 23rd September 2013 
to which we have provided a response you requested further clarification.   You asked:- 
 
You gave a list of all the two-letter prefixes which are currently used or scheduled to be used, 
but I have no way of knowing which have actually been used and which haven't. Could you 
provide a list of the prefixes which are scheduled to be used, but have not yet actually been 
used to issue new NINo's? 
 
Although you didn't specifically answer question 5 (about the single-letter suffixes used) it's 
clear from one of the documents you have referenced (and your reply itself) that only A, B, C, 
D are valid suffixes (although F, M and P were used for temporary numbers). Could you 
confirm that this is correct? 
 
And could you tell me how the single-letter suffix is actually allocated when creating a new 
NINo? E.g. is it random, or is there some method for working it out? (I realise that this wasn't 
part of my original request, but it does save me 
having to make another one, and it would be 
much appreciated.) 
 
DWP Response
Question 1: 
You gave a list of all the two-letter prefixes which are currently used or scheduled to be used, 
but I have no way of knowing which have actually been used and which haven't. Could you 
provide a list of the prefixes which are scheduled to be used, but have not yet actually been 
used to issue new NINo's? 
 
The next pre-fixes due to be used are SS, ST, SX SY and SZ. The use of a new pre-fix will 
commence on the expiry of the prior pre-fix as this is dependant upon the number of NINos 
allocated we cannot provide specific dates. We do not have the information relating to which 
prefixes will be used beyond those mentioned.  

Question 2: 
Although you didn't specifically answer question 5 (about the single-letter suffixes used) it's 
clear from one of the documents you have referenced (and your reply itself) that only A, B, C, 
D are valid suffixes (although F, M and P were used for temporary numbers). Could you 
confirm that this is correct? 
 
Yes, only A, B, C and D are valid suffixes for National Insurance numbers. 
 
Question 3: 
And could you tell me how the single-letter suffix is actually allocated when creating a new 
NINo? E.g. is it random, or is there some method for working it out? (I realise that this wasn't 
part of my original request, but it does save me 
having to make another one, and it would be 
much appreciated.) 
  
The suffixes A, B, C and D are used in rotation.  
If you have any queries about this letter please contact me quoting the reference number 
above.   
Yours sincerely,  
 
 
DWP Central FoI Team 
 
 
------------------------------------------------------------------------------------------------------ 
 
Your right to complain under the Freedom of Information Act 
 
If you are not happy with this response you may request an internal review by e-mailing freedom-of-information-
xxxxxxx@xxx.xxx.xxx.xx or by writing to DWP, Central FoI Team, Caxton House, Tothill Street, London, SW1H 
9NA. Any review request should be submitted within two months of the date of this letter.  
 
If you are not content with the outcome of the internal review you may apply directly to the Information 
Commissioner’s Office for a decision. Generally the Commissioner cannot make a decision unless you have 
exhausted our own complaints procedure. The Information Commissioner can be contacted at: The Information 
Commissioner’s Office, Wycliffe House, Water Lane, Wilmslow Cheshire SK9 5AF www.ico.gov.uk