A Guide to Tax Planning for Businesses in UK

Keeping a business financially healthy isn’t just about selling products or services; it’s also about smart tax planning. In the UK, tax laws change frequently, and missing a deadline can quickly eat into profits. This guide draws on recent guidance from HMRC and recognised tax experts to show how smart tax planning for businesses can help you meet key deadlines and make full use of available allowances.

Understanding the UK Tax Year vs Fiscal Year

The UK operates on a tax year that runs from 6 April to 5 April. This quirky date has its roots in the switch from the Julian to the Gregorian calendar in 1752 — the government extended the tax year to avoid losing revenue when 11 days were dropped from the calendar. While most countries use a calendar year, UK businesses must keep the 6 April start in mind when planning.

A fiscal year or accounting period is the 12‑month cycle a business uses for its own accounts. Companies House automatically sets the year‑end date for a new company to the last day of the month of incorporation, one year later. As per your fiscal year tax planning, you can change this date — shorten it as often as you like or extend it once every five years. Reasons to do so include:

• Aligning with quieter trading periods – having a year-end when business is slow gives you time to prepare accounts.
• Matching the tax year – choosing 31 March or 5 April simplifies dividend planning and aligns company profits with your self-assessment return.
• Delaying a tax bill – bringing the year‑end forward or back can push a corporation tax payment into a later tax year.

Sole traders used to pick any accounting date, but the basis period reform means that, from 2024/25 onwards, all sole traders and partnerships are taxed on profits earned during 6 April to 5 April. Using 31 March or 5 April for the year‑end avoids complex split‑year calculations.

Key Tax Filing Deadlines

Financial tax planning for businesses helps you stay on top of deadlines and avoid penalties and interest charges. The dates below apply to the 2024/25 tax year and the 2025/26 corporation tax cycle.

Self‑Assessment

• Registering – If you need to file a Self Assessment tax return and haven’t done so before, tell HMRC by 5 October 2025.
• Paper return – HMRC must receive your paper tax return by 31 October 2025.
• Online return – Online filings are due by 11:59 p.m. on 31 January 2026. Filing by 30 December 2025 lets HMRC collect tax through your PAYE code.
• Payment – Pay any tax owed by 31 January 2026, or you’ll face penalties. If you make payments on account, the second instalment is due on 31 July 2026.

Filing early avoids the January rush and provides you time to correct errors or claim refunds.

Corporation Tax

• Filing the CT600 – A limited company must file its corporation tax return within 12 months of the end of its accounting period. A company with a year-end date of 31 March 2025 must file by 31 March 2026.
• Paying the tax – Corporation tax must usually be paid nine months and one day after the end of the accounting period. For a 31 March 2025 year‑end, payment is due by 1 January 2026.

Missing these deadlines triggers escalating penalties, starting with a £100 fine and rising to 10% of the unpaid tax if you’re over six months late.

Other Deadlines

• R&D Tax Relief Notification – If your company hasn’t made a valid R&D claim in the last three years, you must pre‑notify HMRC of your intention to claim within six months of your period of account end. Missing this window invalidates your claim.
• Self‑Assessment Non‑residents (SA109) – UK expats who need to claim split‑year treatment or relief under a double‑taxation agreement must submit form SA109 along with their return. HMRC’s online system doesn’t support SA109, so paper filing or specialist software is required.

Choosing the Right Fiscal Year

Selecting a fiscal year that suits your business can simplify tax planning. Here are factors to consider:

• Cash flow and seasonality – Set your year‑end after busy periods so you have downtime to organise records.
• Synchronising multiple businesses – If you own more than one company, aligning year‑ends can streamline bookkeeping.
• Personal tax planning – Companies that pay dividends might prefer a 31 March or 5 April year‑end to align with the personal tax year.

Before changing your accounting reference date, talk to your accountant, as it can affect corporation tax payment dates and Companies House filing deadlines.

Keeping Robust Financial Records

Accurate record-keeping is the backbone of effective financial tax planning for businesses. HMRC expects businesses to retain invoices, receipts, bank statements, payroll records and VAT documents. These records support claims for expenses and reliefs, and they simplify the process of filing returns. A few practical tips:

• Organise everything – Keep digital copies of sales and purchase invoices, bank statements and payroll records. Use cloud accounting software to reduce paper clutter.
• Understand retention rules – In most cases, tax records must be kept for four years from the end of the relevant tax period, but this obligation extends to six, twelve or even twenty years in cases of careless or deliberate behaviour.
• Prepare for audits – Good records make an HMRC inspection less stressful and help you demonstrate that your returns are accurate.

Strategies to Minimise Tax Liabilities

A well‑planned tax strategy can reduce your overall liability while keeping you compliant. Below are common approaches used by professionals, backed by current regulations.

Optimise Salary and Dividends

For owner‑managers of limited companies, balancing salary and dividends can reduce tax and National Insurance. For the 2024/25 tax year:

• Personal allowance – Everyone has a personal allowance of £12,570. Paying yourself a salary up to this limit avoids income tax and employee National Insurance contributions, though employers’ NICs apply above £9,100.
• Dividend allowance – Individuals can receive £500 of dividends tax‑free in 2025/26. Dividends above this are taxed at 8.75%, 33.75% or 39.35%, depending on your income bracket.
• National Insurance changes – From April 2025, employer NICs rise from 13.8% to 15%, and the threshold at which they begin to apply drops from £9,100 to £5,000. This increases the cost of paying salaries, making careful planning more important.

The typical strategy is to take a salary up to the personal allowance and the balance as dividends. This uses the allowance and keeps NICs low.

Pension Contributions

Pension contributions offer generous tax relief. For 2024/25, individuals can contribute up to £60,000 or 100% of earnings (whichever is lower). Company contributions are deductible for corporation tax, and personal contributions attract relief at your marginal rate. Making contributions before the end of the tax year reduces taxable income and preserves unused allowances under carry‑forward rules.

Use ISA and EIS/SEIS Allowances

• Individual Savings Accounts (ISAs) – You can invest up to £20,000 annually in cash, stocks and shares, or innovative finance ISAs. Returns are free of income tax and capital gains tax.
• Enterprise Investment Scheme (EIS) and Seed Enterprise Investment Scheme (SEIS) – Investing in qualifying companies through EIS offers 30% income tax relief, while SEIS offers 50% relief. Both schemes also provide capital gains tax exemptions.

Claim Capital Allowances

Capital allowances let companies deduct the cost of qualifying assets from profits before tax. Options include:

• Annual Investment Allowance (AIA) – Claim up to £1 million on certain plant and machinery.
• Full expensing – For new plant and machinery purchased from 1 April 2023, companies can deduct 100% of the cost in the year of purchase.
• 50% First‑Year Allowance – Where full expensing doesn’t apply, companies can claim 50% of the cost in the first year.

Choosing the right allowance depends on cash flow and the type of asset. Talk to your accountant about maximising relief.

Make the Most of R&D Tax Credits

If your business invests in research and development, R&D tax relief can provide a valuable deduction or cash repayment. Key rules include:

• Pre‑notification – If you haven’t made a valid R&D claim in the last three years, HMRC requires you to notify them of your intent within six months of your period of account end. Missing this deadline means you cannot claim for that period.
• Record keeping – Keep detailed records of qualifying activities and costs; HMRC may deny claims without evidence.

Timing Capital Gains and Gifts

Capital gains tax (CGT) and inheritance tax (IHT) can also be managed with forward planning:

• CGT allowances and rates – The annual exempt amount is £3,000, with basic and higher-rate taxpayers paying 10% or 20% on most assets; for residential property the rates are 18% or 24%. Selling assets when income is lower or before rates rise can save tax.
• Business Asset Disposal Relief (BADR) – Qualifying business assets may be taxed at 10% up to a lifetime limit of £1 million.
• Gifting and IHT – You can give away £3,000 each year without IHT, and small gifts up to £250 don’t count towards the limit. Gifts made more than seven years before death are usually exempt.

Keep an Eye on Changing Rules

Tax rules evolve. Employer NIC rises and Employment Allowance changes highlight how policy can shift mid‑year. Budget announcements may freeze or adjust thresholds (for example, the personal allowance is frozen at £12,570 until at least 2026). Regularly reviewing your tax plan ensures you stay compliant and take advantage of new relief.

How Apex Accountants Tax Planning For Businesses

Apex Accountants understand that tax planning can be complex, and the risks of making mistakes can be costly. Our team of expert tax advisors is here to ensure your business stays on track with the ever-evolving tax landscape. Here’s how we can support you:

1. Expert Tax Guidance

We provide tailored tax advice that aligns with your business’s specific needs. Whether it’s optimising tax relief, exploring R&D tax credits, or choosing the best fiscal year for your company, we offer personalised strategies to reduce tax liabilities while remaining fully compliant with HMRC.

2. Timely Deadline Management

Meeting tax deadlines is critical to avoiding penalties. Apex Accountants will help you stay on top of key submission dates, such as self-assessment and corporation tax returns, ensuring your business never misses a crucial deadline.

3. Accurate Record-Keeping & Financial Reporting

Keeping organised, accurate financial records is essential for tax compliance. We’ll help you implement effective systems to track income, expenses, and tax filings, giving you peace of mind knowing your records are always in order.

4. Strategic Fiscal Year Tax Planning

Choosing the right fiscal year for your business can make a significant difference in your tax planning. Apex Accountants will work with you to determine the most advantageous accounting period for your company, helping you align your fiscal year-end with your business goals.

5. Capital Allowances & Full Expensing

We can guide you through capital allowances, such as full expensing for new plant and machinery. This will enable you to reduce your tax bill by claiming deductions on business assets purchased during the year, which can significantly improve cash flow.

6. Maximising Tax Allowances & Deductions

Our team will work with you to identify all eligible allowances and deductions, such as the dividend allowance, personal allowance, and research and development (R&D) tax credits, to ensure you minimise your tax liabilities.

7. Tax Planning for Growth

Whether you’re scaling up or streamlining operations, Apex Accountants will support your business growth by advising on tax-efficient structures, such as salary and dividend strategies, and providing advice on mergers, acquisitions, and other corporate changes.

Final Thoughts

Effective tax planning isn’t about aggressive schemes; it’s about understanding the rules and using them to your advantage. Align your accounting period with your business cycle, meet filing deadlines, keep detailed records and use available reliefs. With careful planning and professional advice, you can reduce your tax bill and strengthen your company’s financial health. Book a free consultation with us today to discover how effective tax planning strategies can empower your business