Salary Sacrifice vs Relief at Source: Which Pension Method Saves You More?

How Each Method Works

Salary Sacrifice

With salary sacrifice, you and your employer formally agree to reduce your contractual gross salary in exchange for your employer paying that amount directly into your pension. Because the contribution never becomes part of your pay, you never pay income tax or National Insurance on it. Your payslip shows the reduced gross.

Relief at Source (RAS)

With Relief at Source, your employer pays your gross salary as normal, deducts income tax and NI in the usual way, and you make your pension contribution from your net (after-tax) pay. Your pension provider then automatically claims 20% basic-rate tax relief from HMRC and adds it to your pot. Higher-rate and additional-rate taxpayers must claim the extra 20% or 25% relief themselves via Self Assessment.

Tax Savings: Side by Side

The NI Advantage: Why Salary Sacrifice Wins

The critical difference is National Insurance. In 2026/27, employees pay 8% NI on earnings between £12,570 and £50,270. Salary sacrifice avoids NI on the sacrificed amount; Relief at Source does not.

On every £1,000 sacrificed into a pension:

• Salary Sacrifice saves £200 income tax (basic rate) + £80 NI = £280 total
• Relief at Source saves £200 income tax only = £200 total
• The difference: £80 per £1,000 contributed — purely from NI savings

Worked Examples: 2026/27

Example 1: Basic Rate Taxpayer — £35,000 Salary, £2,400/year pension (5%)

Example 2: Higher Rate Taxpayer — £65,000 Salary, £6,000/year pension (10%)

Note: NI is only 2% above the Upper Earnings Limit of £50,270. For the £15,000 portion of this £65k salary above that limit, NI rate is 2% not 8%.

Student Loan Impact

Student loan repayments (9% above threshold for Plans 1, 2, 4, 5) are calculated on your income after salary sacrifice. If you sacrifice £3,000 into a pension:

• Your repayable income falls by £3,000
• You save 9% of £3,000 = £270/year extra on loan repayments
• Relief at Source provides no such saving

Watch-outs for Salary Sacrifice

• Mortgage applications: Lenders typically use your contractual gross salary, which is lower after sacrifice. This can reduce borrowing capacity.
• Statutory Maternity/Paternity Pay: SMP is calculated on average weekly earnings — a lower gross can mean lower SMP payments.
• State Pension: If sacrifice pushes your gross below £6,396 (Lower Earnings Limit 2026/27), you may lose qualifying NI credits for State Pension.
• Not all employers offer it: Salary sacrifice requires your employer to offer the scheme. Relief at Source is available through any pension provider.

Which Should You Choose?

For most employees: salary sacrifice wins on pure numbers, often by a significant margin. The NI saving alone (8% inside the basic rate band, 2% above) consistently makes it more efficient than Relief at Source.

Choose Relief at Source if: your employer doesn't offer salary sacrifice, you're planning a mortgage application and need maximum gross income on record, or you're close to the Lower Earnings Limit and need to protect State Pension credits.