Class 1 National Insurance
Employee and employer Class 1 contributions for explicitly confirmed category A, non-director weekly or monthly pay.
Employee and employer Class 1 contributions for explicitly confirmed category A, non-director weekly or monthly pay.
Reviewed calculation boundary
Reviewed · Current · Official guidance · 6 April 2024 to 5 April 2027
Sterling's calculated path covers category A employees who are not directors, using an explicitly supplied weekly or monthly earnings period and payment date.
The result calculates employee and employer Class 1 separately: the employee primary contribution and the employer secondary contribution. It is a reviewable calculation only: Sterling never runs payroll, posts a payroll journal, submits RTI or pays HMRC from this answer.
Exceptions and branches
- Directors, category letters other than A and non-weekly or non-monthly earnings periods need separate reviewed rules.
- PAYE Income Tax, pensions, student loans, statutory payments, net pay and RTI are outside this calculation.
Explore this calculation
Start with Rates and thresholds, then follow the Exact percentage method for the separate employee and employer arithmetic and rounding rule.
Related concepts
Linked from
Sources
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Social Security Contributions and Benefits Act 1992, section 5 — Section 5. Primary authority.
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Social Security Contributions and Benefits Act 1992, section 6 — Section 6. Primary authority.
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Social Security Contributions and Benefits (Northern Ireland) Act 1992, section 5 — Section 5. Primary authority.
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Social Security Contributions and Benefits (Northern Ireland) Act 1992, section 6 — Section 6. Primary authority.
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CA38: National Insurance contributions tables A and J — Current and archived annual table attachments. Official guidance.
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2026 to 2027: Employer further guide to PAYE and National Insurance contributions — Sections 1.7 and 3. Official guidance.
Knowledge version: sterling-knowledge@2026-09-11.7. Last checked 11 September 2026.