Methodology note
Raise employer National Insurance: note
Models raise employer national insurance in 2027-28. The estimate is illustrative and excludes wider package interactions.
Central fiscal result
-GBP 24.2bn - Net fiscal impact in 2027-28
Low case: -GBP 27.0bn. High case: -GBP 18.0bn. Positive numbers are fiscal costs or borrowing pressure. Negative numbers are Exchequer savings or receipts.
Scenario and baseline
- Models raise employer national insurance by 2027-28.
- Baseline is current policy or published departmental plans.
- Central case uses published party or official anchors where available.
- Wider manifesto interactions are excluded unless stated.
Affected population
- Affected units are people, firms, households or providers depending on policy.
- Direct exposure follows the manifesto or government target group.
- Indirect exposure includes suppliers, workers, consumers and taxpayers.
- Weakest counts are widened in the low and high cases.
Gross impact
- Published anchor or scenario central is +GBP 24.2bn in 2027-28.
- Gross costs or receipts are adjusted for behaviour and delivery risk.
- Tax, benefit or procurement offsets are separated in the fiscal build-up.
- The range is deliberately wider where implementation detail is thin.
Fiscal build-up, central case
- Gross tax or receipt yield: -GBP 30.2bn
- Behavioural and avoidance response: +GBP 4.8bn
- Administration and compliance cost: +GBP 0.1bn
- Other tax-base interactions: +GBP 1.1bn
Central net impact: -GBP 24.2bn in 2027-28.
Behaviour and pass-through
- Low case assumes stronger delivery or receipts than central.
- Central case applies moderate behavioural leakage and pass-through.
- High case allows weaker delivery, larger take-up or higher costs.
- Output effects follow incidence, capacity and investment channels.
- Distributional gains do not automatically imply GDP gains.
Phasing
- 2026-27: -GBP 6.0bn. Phased implementation and take-up.
- 2027-28: -GBP 24.2bn. Phased implementation and take-up.
- 2028-29: -GBP 24.2bn. Phased implementation and take-up.
- 2029-30: -GBP 24.2bn. Phased implementation and take-up.
Main source groups
- S1: HM Treasury: source for scenario or evidence.
- S2: Office for Budget Responsibility: source for scenario or evidence.
- S3: Journal of Public Economics: source for scenario or evidence.
- S4: Handbook of Public Economics: source for scenario or evidence.