| NIM24001 | Class 4 NICs Liability: General |
| NIM24002 | Special Classes 4 NICs: General |
| NIM24003 | Special Classes 4 NICs: Calculation of earnings |
| NIM24004 | Class 4 NICs Liability: Deferment & the annual maximum |
| NIM24005+ | Class 4 NICs: Structure pre 6 April 2003 |
| NIM24030+ | Class 4 NICs: Structure from 6 April 2003 |
| NIM24100+ | Class 4 NICs: Structure: Annual Class 4 NICs maximum pre 6 April 2003 |
| NIM24150+ | Class 4 NICs: Structure: Annual Class 4 NICs maximum from 6 April 2003 |