Class 1 structural overview from April 2009: the Primary Threshold (‘PT’) & the Secondary Threshold (‘ST’)
Section 5, SSCBA 1992 and regulations 10 & 11 SS(C)R 2001
The Primary Threshold (‘PT’) and Secondary Threshold (‘ST’) represent the points from which payment of NICs arises - as opposed to the point at which entitlement to benefit builds up and which is set by the LEL, see NIM01205, The monthly and yearly PT and ST are fixed each year and for years prior to 6 April 2011, see NIM01008
From 6 April 2011, the PT and ST are no longer set at the same level for primary and secondary NICs, see NIM01011. Similarly, from 6 April 2011, the PT and ST are no longer aligned with the Income Tax personal allowance.
For guidance on how to calculate the PT and the ST for pay intervals of other than one month or one year from 6 April 2011, see NIM01210.