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Who must send in a tax return

From self-employment to rental income, there are many reasons you may need to file a Self-Assessment return. Know the triggers and register with HMRC by 5 October if this is your first time.

There are a number of reasons why you might need to complete a self-assessment return. This includes if you are self-employed, a company director, have an annual income over £150,000 and / or have income from savings, investment or property.

You must file a self-assessment tax return if any of the following apply to you during the tax year:

  • You were self-employed as a sole trader and earned more than £1,000 (before expenses).
  • You were a partner in a business partnership.
  • Your total taxable income exceeded £150,000 in the 2025–26 tax year. However, even if your income is under £150,000, other factors (such as rental income or capital gains) may still require you to file a self-assessment return.
  • You had to pay Capital Gains Tax on the sale or disposal of assets.
  • You were liable for the High Income Child Benefit Charge.
  • You had other sources of untaxed income, such as:
    • Rental income from property
    • Tips or commission
    • Savings and investment income (including dividends)
    • Foreign income

If you need to file a self-assessment return for the first time, you must inform HMRC by 5 October following the end of the tax year. For the 2025–26 tax year (which ends on 5 April 2026), the deadline to register is 5 October 2026.

HMRC has an online tool www.gov.uk/check-if-you-need-tax-return/ that can help you check if you are required to submit a self-assessment return.

When do the higher rates of Income Tax apply

Once your income passes £100,000, your tax-free allowance starts to shrink. Between £100,000 and £125,140, the effective tax rate climbs to 60%, but smart planning can help.

If you earn over £100,000 in any tax year your personal allowance is gradually reduced by £1 for every £2 of adjusted net income over £100,000 irrespective of age. This means that any taxable receipt that takes your income over £100,000 will result in a reduction in personal tax allowances.

Your personal Income Tax allowance would therefore be reduced to zero if your adjusted net income is £125,140 or above. Your adjusted net income is your total taxable income before any personal allowances, less certain tax reliefs such as trading losses and certain charitable donations and pension contributions.

If your adjusted net income is likely to fall between £100,000 and £125,140 your £12,570 tax-free personal allowance is gradually tapered. This tapering continues until your allowance is fully withdrawn at an income level of £125,140. This effectively results in a 60% marginal tax rate on income between £100,000 and £125,140.

For example, if your adjusted net income is £110,000, you would lose £5,000 of your personal allowance. This additional £5,000 is taxed at 60% due to the combined effect of the 40% higher rate of Income Tax and the partial loss of the personal allowance.

If your income sits within this band you should consider what financial planning opportunities are available in order to avoid this personal allowance trap by trying to reduce your income below to £100,000. This can include giving gifts to charity, increasing pension contributions and participating in certain investment schemes.

2025 Spending Review published

The government’s 2025 Spending Review outlines a major funding boost for healthcare, defence, housing, and infrastructure to support long-term recovery and growth.

The 2025 Spending Review was published on 11 June 2025 and outlines the government's plans to support the country’s recovery by investing in security, health, and the economy. It sets budgets for government departments up to 2028–29 for everyday spending, and up to 2029–30 for long-term projects like infrastructure. Overall, departmental budgets will grow by 2.3% during this period. The review also sets funding levels for the devolved governments in Scotland, Wales, and Northern Ireland.

This includes a £29 billion investment to revitalise the NHS. The funding aims to modernise the health service, address backlogs, and future-proof care delivery. Specifically, up to £10 billion will be used towards digital transformation and technology. This will include measures to expand GP training to deliver millions more appointments, enhance mental health services in schools.

Beyond healthcare, the Spending Review also set out substantial investments in defence, infrastructure, housing and energy security. This includes £15 billion for a nuclear warhead programme and £6 billion for munitions manufacturing. Border security and asylum processing are also set for major upgrades.. Border security and asylum processing are also set for major upgrades.

The government will also channel billions into local transport, rail links, and regional regeneration projects, while launching the largest social and affordable housing programme in a generation with £39 billion over ten years. The devolved administrations will receive their largest real-terms settlements since devolution began in 1998 to help ensure that locally tailored priorities are funded robustly.

Effects of Rachel Reeves’ Spending Review

Chancellor Rachel Reeves delivered her first Spending Review to Parliament last week, setting out the government’s financial priorities for the next three years. Her approach signals a shift away from austerity towards a strategy of state-backed investment, aimed at boosting growth and productivity while maintaining fiscal credibility.

The review promises a substantial increase in capital spending, with key allocations for transport infrastructure, energy security, housing, and green technology. The government pledged a multi-year uplift in NHS and defence funding, while committing to invest heavily in rail, roads, and nuclear energy projects.

Day-to-day departmental budgets are set to grow modestly in real terms, but the largest gains will be in capital allocations. The spending framework also relies on projected efficiency savings of £14 billion, which will be used to fund some of the more ambitious commitments.

For UK businesses, the implications vary by sector. Construction and engineering firms can expect opportunities from increased infrastructure spending, particularly those aligned with green objectives and transport. Firms in digital healthcare, AI, and clean energy technologies may also see a benefit from targeted support and public procurement opportunities.

Technology businesses are likely to see some growth stimulus through investment in digital public services and AI infrastructure. Similarly, the life sciences and carbon capture sectors are expected to benefit from targeted research and development initiatives.

However, the business community remains cautious. The Spending Review comes at a time when government debt is at historically high levels, and market confidence is sensitive to fiscal overreach. Some forecasters have warned of a potential shortfall of up to £20 billion in the government’s medium-term plans, which could necessitate either tax increases or tighter departmental controls later this year.

There is also concern over the government’s reliance on efficiency savings to meet its commitments. While welcomed in principle, businesses and economists alike remain sceptical about how quickly those savings can be delivered in practice.

In summary, the Spending Review presents a growth-focused and investment-driven agenda. For business, it brings opportunities, particularly in sectors aligned with the government’s infrastructure, green and digital priorities. However, there are risks associated with delivering on these promises if forecasts fall short or efficiency measures do not materialise as planned.

BT Eyes Deeper Job Cuts as AI Reshapes Telecoms

BT has announced that it may exceed its previously stated target of cutting 40,000 jobs by 2030, as artificial intelligence (AI) becomes more central to its operations. The move comes as the company accelerates its cost-cutting programme and seeks to reorient itself in a changing telecoms landscape.

The CEO, Allison Kirkby, who took over in early 2024, has emphasised efficiency, automation, and simplification. Since then, BT has exited international operations, focused more tightly on its UK telecoms core, and made plans to separate out divisions like Openreach to unlock shareholder value.

The company is now embedding AI across key departments, including customer service, fault detection, and network operations. Automation of routine tasks is enabling BT to reduce headcount while aiming to improve efficiency and service delivery. AI-driven tools are being integrated into call centres and technical support functions, with a view to replacing human input for common troubleshooting and account management requests.

The financial rationale is clear. BT is in the midst of a £3 billion cost-reduction programme and has said that increases in employer national insurance contributions alone could cost it £100 million annually. Leveraging AI is seen as one of the few scalable methods of preserving margins while continuing to invest in infrastructure.

This restructuring has important implications across the telecoms sector. Job losses will be concentrated in customer-facing roles and back-office operations. At the same time, there is likely to be increased demand for skilled AI engineers, data analysts, and cybersecurity specialists.

Smaller providers and BT’s supply chain will need to adapt quickly. Companies offering AI systems, automation tools, and support services may find new commercial opportunities, particularly if BT’s adoption drives wider change in the sector.

The risk is that over-automation could impact customer service and employee morale. BT will need to strike a careful balance to maintain brand reputation and service levels, especially as it faces competition from a possible Vodafone–Three merger and new market entrants.

BT’s direction under Kirkby points to a leaner, more tech-led organisation. For investors, this may offer stability and long-term growth. For employees, it signals ongoing transformation and the need for reskilling. For the wider economy, it highlights how AI is moving beyond hype and directly reshaping corporate strategy and workforce planning.