Dropping to a Four-Day Week: Take-Home Impact in 2026/27

Going from five days to four usually means a 20% pay cut, but it rarely means a 20% cut to the money you actually keep. Income tax and National Insurance are removed from the top of your salary first, which softens the blow considerably. This case study models three realistic scenarios for 2026/27, gives you the actual pound figures, and explains what else changes when you reduce your hours. Use the take-home pay calculator to model your own numbers.

The 2026/27 tax and NI framework

All calculations below use the following confirmed 2026/27 rates for England, Wales and Northern Ireland.

Income tax bands (England, Wales and Northern Ireland):

Employee National Insurance (Class 1):

The Personal Allowance has been frozen at £12,570 since 2021/22 and is scheduled to remain there until at least April 2028. Both the Primary Threshold and the Personal Allowance are aligned at £12,570, meaning NI and income tax kick in at the same point.

Example 1: £50,000 dropping to £40,000

This is the most common scenario for a professional on a mid-range salary who moves to a four-day week and accepts a straightforward 20% pay reduction.

Take-home on £50,000 (five days)

• Taxable income: £50,000 minus £12,570 Personal Allowance = £37,430
• Income tax: £37,430 x 20% = £7,486 (all within the basic-rate band, which runs to £37,700 above the allowance)
• Employee NI: £37,430 x 8% = £2,994.40

Take-home: £50,000 minus £7,486 minus £2,994.40 = £39,519.60 per year (£3,293.30 per month)

Take-home on £40,000 (four days)

• Taxable income: £40,000 minus £12,570 = £27,430
• Income tax: £27,430 x 20% = £5,486
• Employee NI: £27,430 x 8% = £2,194.40

Take-home: £40,000 minus £5,486 minus £2,194.40 = £32,319.60 per year (£2,693.30 per month)

The real cost of the lost day

You give up £10,000 of salary but only £7,200 of take-home. The government absorbed £2,800 of the headline cut — £2,000 in income tax and £800 in NI. Expressed differently, each pound of salary reduction only cost you 72p net.

Example 2: £60,000 dropping to £48,000

This scenario crosses the higher-rate threshold. The person currently has income sitting in the 40% band, and the four-day week salary moves them back to basic rate only.

Take-home on £60,000 (five days)

• Taxable income: £60,000 minus £12,570 = £47,430
• Basic-rate tax on the first £37,700: £37,700 x 20% = £7,540
• Higher-rate tax on the remaining £9,730: £9,730 x 40% = £3,892
• Total income tax: £11,432
• NI on earnings from £12,570 to £50,270: £37,700 x 8% = £3,016
• NI on earnings above £50,270: (£60,000 minus £50,270) x 2% = £9,730 x 2% = £194.60
• Total NI: £3,210.60

Take-home: £60,000 minus £11,432 minus £3,210.60 = £45,357.40 per year (£3,779.78 per month)

Take-home on £48,000 (four days)

• Taxable income: £48,000 minus £12,570 = £35,430
• Income tax: £35,430 x 20% = £7,086 (all within basic rate)
• NI: £35,430 x 8% = £2,834.40

Take-home: £48,000 minus £7,086 minus £2,834.40 = £38,079.60 per year (£3,173.30 per month)

What the numbers show

Here the gross pay cut is £12,000 but the net reduction is only £7,277.80 — the tax system absorbed £4,722.20. The effective cost of each pound of salary reduction is just 60.6p in take-home. The reason is that the income between £48,000 and £60,000 was taxed at a combined 42% (40% income tax plus 2% NI above the Upper Earnings Limit), so it was always expensive income to keep.

Use the income tax calculator to see the full band breakdown for your own salary, and the National Insurance calculator to check your NI liability at both salary points.

Example 3: £110,000 dropping to £88,000 (the Personal Allowance taper)

For higher earners the savings from reducing hours are even more dramatic because of the Personal Allowance taper. Income above £100,000 causes the Personal Allowance to be withdrawn at a rate of £1 for every £2 of additional income. At £110,000 your effective allowance is reduced to £7,570 (£12,570 minus £5,000), creating an effective marginal rate of 60% on earnings between £100,000 and £125,140.

Take-home on £110,000 (five days)

• Effective Personal Allowance: £12,570 minus (£10,000 / 2) = £7,570
• Taxable income: £110,000 minus £7,570 = £102,430
• Basic-rate tax: £37,700 x 20% = £7,540
• Higher-rate tax: (£102,430 minus £37,700) x 40% = £64,730 x 40% = £25,892
• Total income tax: £33,432
• NI: (£50,270 minus £12,570) x 8% = £37,700 x 8% = £3,016
• NI above UEL: (£110,000 minus £50,270) x 2% = £59,730 x 2% = £1,194.60
• Total NI: £4,210.60

Take-home: £110,000 minus £33,432 minus £4,210.60 = £72,357.40 per year (£6,029.78 per month)

Take-home on £88,000 (four days)

At £88,000, the Personal Allowance is fully restored. Income above £100,000 is £0, so no taper applies.

• Personal Allowance: £12,570 (full)
• Taxable income: £88,000 minus £12,570 = £75,430
• Basic-rate tax: £37,700 x 20% = £7,540
• Higher-rate tax: (£75,430 minus £37,700) x 40% = £37,730 x 40% = £15,092
• Total income tax: £22,632
• NI at 8%: £37,700 x 8% = £3,016
• NI at 2%: (£88,000 minus £50,270) x 2% = £37,730 x 2% = £754.60
• Total NI: £3,770.60

Take-home: £88,000 minus £22,632 minus £3,770.60 = £61,597.40 per year (£5,133.12 per month)

Comparison

A £22,000 gross reduction produces only a £10,760 net reduction. The effective cost of each pound surrendered is just 48.9p — barely half. Anyone earning in or above the taper zone should model this carefully before deciding. The take-home pay calculator handles the taper automatically.

How pension contributions change the picture

Workplace pension contributions add another layer. Under auto-enrolment the statutory minimum is 3% employer plus 5% employee (total 8%) on qualifying earnings between £6,240 and £50,270. A voluntary or matched employer contribution on a higher salary can be considerably more generous.

Example: 5% employer match on full salary

The total employment cost to the employer falls by £2,500 in employer pension alone, on top of the salary reduction. Your own pension pot receives £500 less per year from employer contributions. Over 20 years to retirement, at a 4% net growth assumption, that £500 per year shortfall compounds to roughly £14,890 less in your pension — a factor worth including in your decision. Use the pension calculator to model contributions at both salary levels.

Salary sacrifice: does it still work at a lower salary?

If you currently use a salary sacrifice arrangement — for electric vehicle leasing, pension top-up, or a cycle to work scheme — check whether the arrangement remains viable at the reduced salary. Salary sacrifice cannot legally reduce your cash pay below the National Living Wage for your contracted hours.

In 2026/27 the National Living Wage is £12.21 per hour for workers aged 21 and over. On a four-day week at 32 hours, the minimum annual salary equates to approximately £20,315. If your reduced salary remains comfortably above this floor and your sacrifice amount is unchanged in cash terms, the arrangement generally continues — and the tax and NI saving from sacrifice is proportionally just as valuable. The salary sacrifice calculator shows the net benefit at any salary.

Child Benefit and the High Income Child Benefit Charge

The High Income Child Benefit Charge (HICBC) in 2026/27 starts clawing back Child Benefit once either partner earns above £60,000, and removes it entirely at £80,000. If your current salary places you inside this range, reducing your hours could be particularly valuable.

Child Benefit rates in 2026/27 are £26.05 per week for the eldest child and £17.25 per week for each additional child. For two children, that is £2,235 per year. If your salary drops from, say, £68,000 to £54,400, you move below the £60,000 threshold entirely and reclaim the full benefit — worth £2,235 for two children. That additional recovery reduces the true net cost of the working day you have given up.

Other things to weigh up before deciding

Going part time is a lifestyle decision as much as a financial one, but understanding the real numbers gives you a sound basis for negotiation.

• Hourly rate parity: confirm your employer is reducing salary proportionally. Divide your current annual salary by 5 and multiply by 4. If the figure offered is lower, your effective hourly rate has been cut.
• Benefits linked to salary: life assurance, group income protection, and private medical cover are often a multiple of or percentage of salary. Confirm how each changes.
• Future pay progression: some pay bands and bonus schemes refer to full-time equivalent. Understand how part-time working is treated before agreeing.
• Student loan repayments: Plan 2 repayments are 9% of income above £27,295. A salary reduction reduces monthly repayments, providing a small additional cushion on take-home.
• State Pension: your State Pension entitlement depends on qualifying National Insurance years, not earnings levels, provided you earn above the Lower Earnings Limit (£6,396 in 2026/27). A four-day week at a normal salary will still accrue qualifying years at the same rate.

Use the calculator for your own figures

Every salary, pension arrangement and personal situation is different. The examples above use a standard rest-of-UK tax code (1257L) and no additional deductions. Your own calculation may differ if you have multiple income sources, a Scottish tax code, a student loan deduction, or a salary sacrifice arrangement already in place.

Model your current and proposed salary using the take-home pay calculator to see the precise monthly and annual difference. Cross-check your income tax position with the income tax calculator and your National Insurance with the National Insurance calculator. If pension contributions are a significant factor, the pension calculator will show how contributions change on both salary figures.

All tax and NI rates are sourced from HMRC and confirmed on gov.uk. This article is general information only and does not constitute financial, tax or employment advice. Consult a qualified adviser before making decisions about your working arrangements.