Statutory Maternity Pay (SMP) is the minimum amount a UK employer must pay an employee during maternity leave, and calculating it correctly requires understanding the earnings test, the two-tier rate structure, and the interaction with employer enhancements. SMP is not discretionary — if your employee qualifies, you are legally required to pay it.

The calculation involves two distinct phases: 90% of average weekly earnings for the first 6 weeks, then a flat rate or 90% of average weekly earnings (whichever is lower) for the remaining 33 weeks. This guide breaks down every step with worked examples.

Key takeaways

  • SMP is paid for 39 weeks: 6 weeks at 90% of average weekly earnings, then 33 weeks at the flat rate (£184.03 in 2025/26) or 90% of average weekly earnings, whichever is lower.
  • To qualify, the employee must have 26 weeks of continuous employment ending in the 15th week before the expected week of childbirth, and earn at least the Lower Earnings Limit.
  • SMP is not pro-rated for part-time workers — it is calculated on actual earnings.
  • Employer-enhanced maternity pay may top up SMP to full salary for a specified period.
  • SMP is subject to tax and National Insurance deductions.

Eligibility criteria

An employee qualifies for SMP if they:

  1. Have been employed for at least 26 continuous weeks ending in the 15th week before the expected week of childbirth
  2. Earn at least the Lower Earnings Limit per week (£123/week for 2025/26)
  3. Give the correct notice (at least 15 weeks before the expected week of childbirth)
  4. Provide a MAT B1 certificate from a doctor or midwife

The 26-week qualifying period is tested at the beginning of the 15th week before the expected week of childbirth. If the employee does not meet this test, they may be eligible for Maternity Allowance instead.

The two-tier SMP rate

Phase 1: 90% of average weekly earnings (first 6 weeks)

SMP starts at 90% of the employee’s average weekly earnings for the first 6 weeks. There is no upper cap on this phase — if the employee earns £2,000/week, they receive £1,800/week for 6 weeks.

Phase 2: Flat rate or 90% (whichever is lower) for weeks 7-39

From week 7, SMP is the flat rate (£184.03 per week for 2025/26) or 90% of average weekly earnings, whichever is lower. For most employees, the flat rate applies because 90% of their earnings exceeds the flat rate.

Calculating average weekly earnings

Average weekly earnings are calculated on the 8 weeks prior to the 15th week before the expected week of childbirth.

Formula

Average weekly earnings = gross pay in the 8-week qualifying period ÷ 8

Worked example 1: High earner

  • Employee earns £60,000/year (£1,153.85/week gross)
  • 8-week qualifying period gross pay: £9,230.80
  • Average weekly earnings: £9,230.80 ÷ 8 = £1,153.85

SMP calculation:

  • Weeks 1-6: 90% × £1,153.85 = £1,038.47/week
  • Weeks 7-39: Flat rate £184.03 (lower than 90% × £1,153.85 = £1,038.47)
  • Total SMP over 39 weeks: (6 × £1,038.47) + (33 × £184.03) = £6,230.82 + £6,072.99 = £12,303.81

Worked example 2: Low earner

  • Employee earns £22,000/year (£423.08/week gross)
  • 8-week qualifying period gross pay: £3,384.64
  • Average weekly earnings: £3,384.64 ÷ 8 = £423.08

SMP calculation:

  • Weeks 1-6: 90% × £423.08 = £380.77/week
  • Weeks 7-39: Flat rate £184.03 (lower than 90% × £423.08 = £380.77)
  • Total SMP over 39 weeks: (6 × £380.77) + (33 × £184.03) = £2,284.62 + £6,072.99 = £8,357.61

Worked example 3: Very low earner

  • Employee earns £15,000/year (£288.46/week gross)
  • 8-week qualifying period gross pay: £2,307.68
  • Average weekly earnings: £2,307.68 ÷ 8 = £288.46

SMP calculation:

  • Weeks 1-6: 90% × £288.46 = £259.61/week
  • Weeks 7-39: Flat rate £184.03 (lower than 90% × £288.46 = £259.61)
  • Total SMP over 39 weeks: (6 × £259.61) + (33 × £184.03) = £1,557.66 + £6,072.99 = £7,630.65

Employer-enhanced maternity pay

Many employers enhance SMP above the statutory minimum. Common structures include:

  • Full pay for X weeks, then SMP — the employer pays 100% of salary for a set period, replacing SMP during that time
  • Full pay minus SMP for X weeks — the employer tops up SMP to full salary
  • Full pay throughout — the employer pays 100% for the entire leave period

Important: The employment contract must specify whether enhanced pay is inclusive of or in addition to SMP. This distinction affects the total amount the employee receives.

Interaction with other benefits

  • Pension contributions continue during Ordinary Maternity Leave (first 11 weeks) on the same basis as before leave.
  • Annual leave continues to accrue during maternity leave.
  • Student loan repayments continue based on SMP (and enhanced pay where applicable).

Putting it into practice

Five checks to ensure your SMP calculations are correct:

  1. Confirm the employee meets the 26-week qualifying period and earnings test.
  2. Calculate average weekly earnings from the correct 8-week qualifying period.
  3. Apply the two-tier rate correctly (90% for 6 weeks, flat rate or 90% for 33 weeks).
  4. Check the employment contract for enhanced maternity pay provisions.
  5. Report SMP through RTI and pay on the normal payroll cycle.
You can take advantage of the free 14 days trial and explore Leave Balance.

Leave Balance auto-calculates SMP from the qualifying period through the 39-week entitlement, handles enhanced maternity pay on top, and manages keeping-in-touch days — so maternity pay is always accurate and on time.

Frequently asked questions

How much is SMP in the UK?

SMP is 90% of average weekly earnings for the first 6 weeks, then the flat rate (£184.03 per week for 2025/26) or 90% of average weekly earnings, whichever is lower, for the remaining 33 weeks.

Can I get SMP if I am self-employed?

No. SMP is only available to employees. Self-employed individuals may be eligible for Maternity Allowance through the Benefits Agency.

Does SMP include bonuses and commission?

Yes. SMP is based on gross pay, which includes regular bonuses, commission, overtime, and shift allowances paid during the 8-week qualifying period. One-off or irregular payments may be excluded depending on the nature of the payment.

Can my employer top up SMP?

Yes. Many employers offer enhanced maternity pay above the statutory minimum. The terms are set out in the employment contract. Enhanced pay may be full pay for a period, a percentage top-up, or a fixed amount.

What happens if my earnings change during the qualifying period?

SMP is calculated on the 8-week qualifying period, so changes in earnings during that period are averaged out. If the employee received a pay rise or bonus during the qualifying period, this increases the average and therefore the SMP amount.

This article is general information, not legal advice. Consult qualified employment counsel for jurisdiction-specific guidance.