Personal Public Service (PPS) numbers are allocated by the Department of Social Protection. Based on the most recent analysis it is estimated that the remaining stock of usable numbers will be exhausted during 2014. The PPS number is a unique personal identifier and is used extensively by Government Departments and other authorised users to provide the public with secure access to a wide range of public services. The PPS number is also used by employers in the calculation of payroll deductions for PAYE tax and PRSI and the delivery of pay, tax and PRSI details to the Revenue Commissioners.
The information below on the new range of PPS numbers only applies to new PPS numbers which are issued on or after 1 st January 2013. If you are already the holder of a PPS number, or you are issued a new PPS number before 31 st December 2012, your PPS number will not be changed and will continue to be valid after 1 st January 2013 for all interactions you may have with Public Service bodies who are authorised to use the PPS number.
Format of current PPS numbers
The PPS number is currently defined as having 9 characters in length. The actual number consists of 7 numeric characters in positions 1 to 7, followed by 1 alphabetic check character in position 8, and either a space or the letter “W” in the position 9 (Level “W” numbers were traditionally allocated to married women and were based on the husband’s PPS number with a “W” added in position 9).
New range PPS numbers
With effect from 1 st January 2013 the Department will be introducing a new range of PPS numbers by including an additional alphabetic character, other than “W”, in position 9 (e.g. 1234567TA).
The alpha character in position 8 will continue to operate as the check character for all existing and new numbers. Accordingly the calculation used (Modulus 23) to produce this character will be revised to avoid any confusion between an “old” number and a “new” number using the same 7 numeric values in the first 7 positions – see note below on the operation of the Modulus 23 calculation.
Benefits of approach chosen
The solution for extending the PPS number range will have the following benefits:
- The solution is not introducing a new format for the PPS number but simply extending the range of the existing one. This will help minimise the impact for users on ICT systems as the length of the PPS number is not being changed.
- The new number range will not require any changes to existing forms as the field size will remain unchanged.
- ICT Systems that only read the PPS number will not need to be changed. Those systems that check the number will require a new checksum calculation.
- All existing PPS numbers will remain unchanged, with only the new numbers and existing level “W” numbers having a non-blank alphabetic character in position 9.
- The stock of available new PPS numbers will be significantly increased – almost 10 million new numbers for each letter of the alphabet used in position 9. This will provide a considerable amount of ‘future proofing’.
Modulus 23 calculation
The alphabetic check character in position 8 is calculated using a weighted addition of all the numbers and a modulus 23 calculation. It therefore checks for incorrectly entered digits and for digit transposition - digits in the wrong order will alter the sum due to the weightings.
The alphabetic character in position 8 will continue to operate as a check character for all existing and the new range of PPS numbers. To avoid any confusion between an “old” number and a “new” number using the same 7 numeric values in the first 7 positions, the modulus 23 calculation will be revised as follows:
- A numeric value will be allocated to the new alphabetic character in position 9, with “A” = 1, “B” = 2, C = 3, etc. An existing “W” or a blank will be allocated a numeric value of zero.
- A weighting of 9 will be assigned to the numeric equivalent of the alphabetic character in position 9.
- Accordingly the check character for the “old” number 1234567 is “T”, whereas the check character for the “new” number 1234567_A will be “F”.
The new Modulus 23 calculation will not alter the alphabetic check character for existing PPS numbers as a numeric value of zero will be applied to a blank or a “W” in position 9.