Corporation tax compliance for UK businesses

Corporation Tax

Corporation tax compliance is deadline-driven work that most businesses lack in-house expertise for. We act as your external finance team, preparing and reviewing CT600 returns, calculating liabilities, computing capital allowances and handling disallowable expense adjustments under current HMRC rules.

Our corporation tax support

CT600 preparation

Your company tax return, reconciled to statutory accounts and ready for review.

Tax computations

Reconciling accounting profit to taxable profit, including standard adjustments and disallowable items.

Tax working papers

Referenced working papers supporting every figure, built for audit trail and sign-off.

Capital allowances

Qualifying expenditure, annual investment allowance, full expensing and writing-down allowance claims.

Loss relief

Trading loss carry-back, carry-forward and group relief options.

Group relief support

Group relief claims and surrenders across connected companies.

Deferred tax

FRS 102 and FRS 105-compliant deferred tax calculations.

R&D tax relief support

Review of qualifying expenditure, claim calculation and supporting documentation.

Marginal relief

Calculations for profits between the small profits rate and main rate thresholds.

Quarterly instalment payments

Forecasting and scheduling for large companies paying by instalments.

HMRC correspondence

Responses, technical analysis and supporting schedules for enquiries.

Tax planning support

Scenario modelling and relief identification for financial decisions.

Why corporation tax compliance matters

Late or incorrect filings can lead to HMRC penalties, interest and formal enquiries. Accurate filing protects your standing with HMRC and makes sure you neither overpay nor miss reliefs.

  • Avoiding HMRC penalties
  • Meeting statutory obligations
  • Maintaining business credibility
  • Financial transparency
  • Effective tax planning
  • Cash flow management
  • Investor confidence
  • Risk reduction

Corporation tax deadlines

RequirementDeadlineWhy it matters
Corporation tax registrationWithin 3 months of starting to tradeFailure to register can result in penalties
Accounting periodUsually your financial year (max 12 months)The basis for all tax calculations
Corporation tax payment9 months and 1 day after period endLate payment triggers interest
CT600 submission12 months after period endLate filing penalties apply immediately
Statutory accounts filing9 months after year end (private companies)Companies House penalties apply
Confirmation statementAt least every 12 monthsNon-filing can lead to strike-off
Record retentionAt least 6 years from period endNeeded to support figures in an enquiry
Quarterly instalmentsLarge companies, paid in-yearInterest on underpaid instalments

FAQs

Frequently asked questions

What is corporation tax?

A tax on the taxable profits of UK limited companies and certain other organisations, reported to HMRC on the CT600 return.

Who needs to file a CT600?

Every UK limited company must file one for each accounting period, even if no tax is due.

What is included in your service?

CT600 preparation and filing, computations, capital allowances, loss relief, group relief, deferred tax, R&D relief support, marginal relief and full working papers.

Can you assist with HMRC enquiries?

Yes, by preparing supporting schedules and technical analysis.

Which software do you use?

IRIS, CCH, TaxCalc, BTCSoftware, Sage, Xero, QuickBooks, FreeAgent, CaseWare and Excel.

How secure is my financial information?

Encrypted platforms, restricted access controls and confidentiality agreements aligned with UK GDPR.

Do you provide tax planning support?

Yes, by identifying reliefs, allowances and structuring opportunities.

Let's reduce your business costs

Book a free, no-obligation consultation and see how much time and money our team can save you.