The UK tax year runs from 6 April 2026 to 5 April 2027, and planning early can save you money, stress, and penalties. Here’s what you need to know to stay ahead.

Key Dates for 2026/27

• 31 January 2026 – Online tax return and payment deadline for 2024/25; first payment on account for 2025/26.
• 5 April 2026 – End of the tax year; last chance for ISA and pension contributions.
• 19 April 2026 – Final PAYE payroll submission for employers.
• 6 July 2026 – Deadline for P11D forms for employee benefits
• 6 April 2026 – Start of the 2026/27 tax year.
• 31 January 2027 – Online tax return and payment deadline for 2025/26.
• 5 April 2027 – End of the tax year; last chance for ISA and pension contributions.
• 19 April 2027 – Final PAYE payroll submission for employers.
• 6 July 2027 – Deadline for P11D forms for employee benefits.

Allowances and Reliefs to Use Before 5 April 2027

• Personal Allowance: Plan to optimise your annual allowance.
• ISA Allowance: Plan to optimise your annual allowance per person.
• Pension Contributions: Plan to optimise your annual allowance (subject to tapering for high earners).
• Capital Gains Tax Annual Exemption: Can you plan for a gain to take advantage of the allowance?
• Marriage Allowance: Transfer some of your unused allowance to your spouse.
• Business Reliefs: Annual Investment Allowance; full expensing for qualifying plant and machinery. Limits apply.

Common Mistakes People Make

• Missing Deadlines: Late filing triggers £100 penalties and daily fines.
• Not Claiming All Reliefs: Many overlook pension tax relief, Marriage Allowance, or allowable business expenses.
• Poor Record-Keeping: HMRC requires records for at least 6 years.
• Ignoring Tax Changes: Frozen allowances mean more people drift into higher tax bands.
• Misclassifying Income: Mixing personal and business expenses can lead to audits.

Making Tax Digital (MTD): What’s Changing in 2026

From 6 April 2026, Making Tax Digital for Income Tax Self Assessment (MTD for ITSA) becomes mandatory for:

• Sole traders and landlords with gross income over £50,000.
• You must:
• Keep digital records using MTD-compatible software.
• Submit quarterly updates to HMRC (deadlines: 7 August, 7 November, 7 February, 7 May).
• Finalise your annual tax return digitally.

Future phases:

• April 2027: Threshold drops to £30,000.
• April 2028: Threshold drops to £20,000.

Why it matters: MTD aims to reduce errors, improve real-time tax visibility, and streamline compliance. Missing quarterly updates will trigger penalties under HMRC’s new points-based system.

How MyController Helps You Stay Compliant

At MyController, we make tax planning proactive:

• Dashboard Alerts for key deadlines and quarterly MTD updates.
• Concierge Finance Service to coordinate with your accountant and solicitor.
• Real-Time Tracking of allowances and reliefs.
• Integrated Planning Tools for ISAs, pensions, and business investments.

✅ Take Action Today

Don’t wait until January—start planning now to maximise allowances and avoid penalties.

👉 Book a Free Consultation with MyController and make 2026 your most tax-efficient year yet.