Corporation Tax Filing Software
Prepare and file your CT600 corporation tax return with AI. TaxStats AI auto-calculates adjusted profits, claims capital allowances, and generates HMRC-ready computations. The smart replacement for CATO.
CT600 software with AI-checked computations. Built for small companies and accounting practices.
CT600 Preparation and Filing
TaxStats AI guides you through the complete CT600 corporation tax return. Enter your trial balance figures — the AI calculates adjusted trading profits, applies capital allowances, handles loss reliefs, and computes your corporation tax liability. Every box reference is included, with supporting schedules and workpapers.
CATO Is Closing — Be Ready
HMRC's Company Accounts and Tax Online (CATO) portal closes on 31 March 2026. If you currently use CATO to file CT600 returns, you need alternative software now. TaxStats AI is MTD-compatible and ready to handle your corporation tax filings — with the added benefit of AI-powered calculations and error checking.
AI-Guided CT600 Workflow
Don't know where to start? TaxStats AI walks you through the CT600 step by step. It asks the right questions about your company's activities, identifies which sections need completing, and populates the return automatically. For experienced accountants, the AI speeds up computation preparation by handling the calculations while you focus on the advisory work.
Auto-Calculates Adjusted Profit
TaxStats AI automatically handles the adjustments from accounting profit to taxable profit: disallowable expenses, capital allowances (AIA, WDA, FYA, SBA, full expensing), trading losses, non-trading loan relationship deficits, and intangible fixed asset adjustments. Associated company rules and marginal rate calculations are handled automatically.
Sound Familiar?
- ✗ HMRC's CATO portal closing on 31 March 2026 — need to find alternative software
- ✗ Complex adjusted profit calculations with multiple add-backs and deductions
- ✗ Missing capital allowance claims costing your clients money
- ✗ Spending hours formatting CT600 computations manually
TaxStats AI solves all of these. Let AI handle the heavy lifting so you can focus on what matters.
“TaxStats AI has completely transformed how we handle tax returns. What used to take hours now takes minutes, and the accuracy is remarkable.”
— Senior Partner, Manchester Accounting PracticeEverything You Need
CT600 Returns
Complete CT600 preparation with all supplementary pages and iXBRL tagging.
Capital Allowances
AIA, WDA, FYA, SBA, and full expensing calculations — claim the maximum entitlement.
R&D Tax Credits
RDEC scheme calculations with qualifying expenditure assessment and technical narrative.
Loss Relief
Carry back, carry forward, group relief, and consortium relief modelling.
CATO Replacement
Full replacement for HMRC's closing CATO portal. File CT600 returns online.
Tax Computations
Generate formatted corporation tax computations in XLSX and PDF for client review.
Frequently Asked Questions
When is Corporation Tax due?
Corporation Tax payment is due 9 months and 1 day after the end of your accounting period, and the CT600 return is due 12 months after the period end. Note the payment deadline falls before the filing deadline.
Can TaxStats AI prepare a CT600?
Yes — it prepares the Corporation Tax computation from your accounts, applies reliefs and allowances such as capital allowances, and produces a CT600-ready computation with the workings shown for review.
What is the small profits rate of Corporation Tax?
UK Corporation Tax has a small profits rate for companies with lower profits and a main rate above that, with marginal relief in between. TaxStats AI applies the correct rate and marginal relief calculation for your accounting period automatically.
File Your CT600 Before the CATO Deadline
CATO closes 31 March 2026. Switch to TaxStats AI now — free plan available, no credit card needed.