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HMRC internal manual

National Insurance Manual

Class 1 Structural Overview: The Primary Threshold ('PT') and the Secondary Threshold ('ST')

Section 5, SSCBA 1992 and regulations 10 & 11

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 (NIM01005). The monthly and yearly PT and ST are fixed each year. For guidance on how to calculate the PT and the ST for pay intervals of other than one month or one year, see NIM01010.

For further guidance on NICs thresholds, see NIM11000 onwards.  If aggregation of earnings is involved (NIM01004), see also NIM10000 onwards.