United Kingdom tax deadlines 2026.
Every individual and self-employed income tax deadline for United Kingdom in 2026. Plus recurring VAT / GST / sales tax filings. Each deadline links to notes on how to file, what people miss, and matching open-source tax skills.
Annual deadlines
2 this yearSelf Assessment Online Filing
GBHMRC online Self Assessment deadline for the 2024/25 tax year (ending April 5, 2025). Also the deadline for the first balancing payment and the first payment on account for 2025/26.
Self Assessment 2nd Payment on Account
GBThe second payment on account for the 2025/26 tax year — typically 50% of the prior year's total liability.
Recurring filings
VAT / GST / Sales taxVAT Return (VAT100) — Making Tax Digital
United Kingdom
UK VAT return filed quarterly under Making Tax Digital. Returns are due one month and seven days after the end of each VAT quarter.
Open-source skills for United Kingdom
Prepare this return with open-source skills
These skills are in the OpenAccountants repo. Add them to your AI agent and they handle the computation.
Use this skill whenever asked to prepare, review, or classify transactions for a UK VAT return (VAT100) for a self-employed individual or very small business in Great Britain. Trigger on phrases like "prepare VAT return", "do my VAT", "classify these for VAT", "VAT100", "9-box return", "MTD", "Making Tax Digital", "flat rate scheme", "FRS", "cash accounting VAT", "input tax", "output tax", "reverse charge construction", "CIS reverse charge", "bad debt relief", "Box 1 to Box 9", "reduced rate UK", "zero-rated UK", "exempt supply UK", "de minimis VAT", "annual accounting scheme", or any question about UK VAT obligations. Covers the VAT100 9-box structure, standard/reduced/zero rates, registration threshold (GBP 90,000), Flat Rate Scheme, cash accounting scheme, annual accounting scheme, MTD requirements, input tax blocked categories, partial exemption, bad debt relief, and reverse charge for construction (CIS). MUST be loaded alongside vat-workflow-base v0.1 or later (for workflow architecture). ALWAYS read this skill before touching any UK VAT work.
Use this skill whenever asked about UK income tax for individuals filing SA100 Self Assessment. Trigger on phrases like "income tax UK", "SA100", "personal allowance", "tax bands", "tax computation", "marriage allowance", "savings allowance", "dividend allowance", "Scottish tax rates", "payments on account", "tax reducers", "tax relief", "April 2026", "2026-27", "Autumn Budget 2025", "income tax bands frozen 2027-28", or any question about computing a UK individual's income tax liability. Covers personal allowance (including taper), income tax bands for rUK and Scotland, marriage allowance, savings and dividend allowances, tax reducers, the final tax computation, payments on account, and the Autumn Budget 2025 changes from April 2026. ALWAYS read this skill before touching any UK income tax return work.
Use this skill whenever asked about UK dividend income taxation. Trigger on phrases like "dividend tax UK", "dividend allowance", "dividend income", "company dividends", "director dividends", "salary vs dividends", "dividend voucher", "SA100 dividends", "foreign dividends UK", "dividend waiver", "dividend tax rates", "8.75%", "33.75%", "39.35%", "10.75%", "35.75%", "April 2026 dividend hike", "Autumn Budget 2025 dividend", "Scottish dividend tax", or any question about computing, declaring, or optimising dividend income for UK individual taxpayers. Covers dividend allowance, rates, salary-vs-dividend planning for company directors, foreign dividends and double tax relief, dividend waivers, and interaction with other income. ALWAYS read this skill before touching any UK dividend work.
Use this skill whenever asked about UK payroll, PAYE, National Insurance contributions, employer obligations, RTI submissions, statutory payments, or payslip requirements. Trigger on phrases like "PAYE", "National Insurance", "NIC", "Class 1 NI", "employer NI", "employee NI", "RTI", "FPS", "EPS", "real time information", "P45", "P60", "P11D", "statutory sick pay", "SSP", "statutory maternity pay", "SMP", "national minimum wage", "national living wage", "payslip", "tax code", "student loan deduction", "workplace pension", "auto-enrolment", "HMRC payroll", or any question about running payroll in the United Kingdom. ALWAYS read this skill before processing any UK payroll work.
Use this skill whenever asked about UK transfer pricing rules, documentation, or HMRC compliance. Trigger on phrases like "transfer pricing UK", "UK TP documentation", "HMRC transfer pricing", "arm's length UK", "master file UK", "local file UK", "CbCR UK", "APA HMRC", "TIOPA Part 4", "Transfer Pricing Records Regulations 2023", or any question about intercompany pricing compliance for UK entities.
Use this skill whenever asked about reducing tax in the UK, tax planning, saving tax, optimizing tax, allowances, deductions the client might be missing, or any question about legal strategies to minimize income tax liability for self-employed individuals in the UK. Trigger on phrases like "reduce tax", "tax planning", "save tax", "optimize", "allowances", "deductions I'm missing", "pay less tax", "tax-efficient", "tax minimization", "how to lower my tax bill". ALWAYS read this skill before advising on any UK tax optimization strategy.
Use this skill whenever asked about UK Student Loan repayment for self-employed individuals. Trigger on phrases like "student loan repayment", "Plan 1", "Plan 2", "Plan 4", "Plan 5", "Plan 5 student loan", "Postgraduate loan repayment", "postgraduate loan", "April 2026 student loan threshold", "student loan self-employed", "student loan Self Assessment", "SLC repayment", "student loan deduction", or any question about student loan obligations for a self-employed client. Also trigger when classifying bank statement transactions showing SLC repayments via SA, PAYE student loan deductions, or direct SLC payments. This skill covers Plan 1-5 and Postgraduate Loan thresholds across three tax years (2024-25, 2025-26, 2026-27), self-employed SA calculation, multiple plan interaction, bank statement classification patterns, overseas earnings, write-off periods, and edge cases. ALWAYS read this skill before touching any UK student loan repayment work.
Use this skill when preparing, reviewing, or advising on annual financial statements for a UK company. Trigger on phrases like "Companies House accounts", "FRS 102", "FRS 105", "micro-entity accounts", "small company accounts", "abbreviated accounts", "directors' report UK", "filing accounts UK", "audit exemption UK", "year-end adjustments UK", "iXBRL", "abridged accounts", or any question about preparing statutory accounts under the Companies Act 2006. Covers FRS 102/105 frameworks, size thresholds, required statements, P&L and balance sheet formats, notes, filing deadlines, and audit requirements.
Preparing a United Kingdom return?
The OpenAccountants repo has verified, open-source tax computation skills. Clone and run them with your AI agent, then get an accountant to review.