Best CT600 Filing Software in 2026: WeFile vs TinyTax, TaxPipe, TaxCalc & TaxFiler

Filing your Corporation Tax return (CT600) is an annual obligation for every UK limited company — whether you're actively trading or dormant. Until now, many small businesses relied on HMRC's free online filing service. But with HMRC confirming the closure of its free CT600 filing portal on 31 March 2026, every company director and accountant needs to find a reliable commercial alternative.

The good news? There are more options than ever. The challenge? They vary enormously in pricing, features, ease of use, and who they're designed for.

In this guide, we provide a detailed, honest comparison of the leading CT600 filing solutions available in 2026 — including our own platform, WeFile — so you can make an informed decision.

Updated 15 August 2026 — WeFile has shipped a great deal since this guide was first published, including CT600A (loans to participators and s455 tax), free MTD VAT filing, free company formation, agent filing, and a full set of FRS 102 accounts notes. Those additions are summarised in New in WeFile Since This Guide Was Published and reflected in the comparison tables below.

HMRC's legacy online filing system has been running for over a decade. It no longer meets modern digital, legislative, or security standards. As part of the Making Tax Digital (MTD) initiative, HMRC is requiring all businesses to use commercial software for CT600 submissions from April 2026 onwards.

This means:

• No more free filing through HMRC's website
• All CT600 returns must be submitted via HMRC-recognised commercial software
• iXBRL-tagged accounts are mandatory for both HMRC and Companies House

If you haven't already chosen a software provider, now is the time.

WeFile was purpose-built to make CT600 and Companies House filing as straightforward as possible — whether you're a solo director filing once a year or an accountant managing dozens of clients.

Pricing

• Dormant company filing: £15 per filing
• Trading company filing: £25 per filing
• Accountant Membership: £250/year for up to 100 filings (as little as £2.50 per filing)
• Developer API: £500/year with 300-filing limit for programmatic submissions
• MTD VAT returns: free for every user — no membership needed
• Company formation: free if you file it yourself, or £15 agent fee plus the Companies House incorporation fee if you'd rather WeFile handled it

Key Features

• Multi-step filing wizard — guided, jargon-free process from start to finish
• Automatic profit & loss and balance sheet generation with intelligent tax calculations
• Dual filing — submit to both HMRC and Companies House from one place
• Dormant accounts supported at a reduced price
• Companies House API integration — automatically fetches your company details and filing periods
• iXBRL accounts generated automatically
• AI Assistant — get help understanding your filing in plain English
• REST API — for developers and platforms wanting to automate filings programmatically
• White-Label Portal — accountants can offer branded filing to their own clients
• Marginal relief calculated automatically across financial years, with associated companies taken into account
• CT600A supplementary pages — loans and arrangements to participators with s455 tax worked out at the correct rate, relief for repayments, and automatic carry-through into Boxes 480, 485, 510 and 525
• MTD VAT returns — HMRC-recognised VAT filing included free for every user
• Company formation — incorporate a UK limited company free, or let WeFile act as your formation agent
• Full FRS 102 1A notes — tangible fixed assets movements, debtors and creditors breakdowns, plus your own custom notes with proper tables and subtotal rows
• Agent filing mode — file as an agent on behalf of client companies with a dedicated Agent block in the HMRC XML
• Amendments to both HMRC and Companies House, even for returns originally filed elsewhere
• No subscription required — pay only when you file

Who it's for: Solo directors, small companies, accountants, bookkeepers, and developers who want a modern, no-nonsense filing experience at a fair price.

This guide first went live on 1 June 2026. Since then WeFile has shipped continuously — every item below is live today, and the full running list is on our changelog.

CT600A — loans to participators and s455 tax (August 2026)

The single biggest addition. Confirm on step 1 of the wizard that you're a close company and a Loans step appears, where you record loans and arrangements to participators. WeFile then:

• Calculates s455 tax at the rate in force when each loan was made — 25%, 32.5%, 33.75%, and 35.75% from 6 April 2026
• Handles relief for loans repaid, released or written off, working out from the nine-month deadline whether each entry belongs in Part 2 or Part 3 of the form
• Derives Box A75 (total loans outstanding) and Box A80 (s455 payable), then carries them into main-form Boxes 480, 485, 510 and 525 and ticks Box 95 for you
• Submits CT600A inside the same CT600 return — no separate filing — and gives you the completed CT600A as its own PDF
• Keeps s455 out of your statutory accounts, so the P&L and the iXBRL accounts filed at Companies House are untouched
• Supports split return periods, allocating loans by the date advanced

Free MTD VAT filing (August 2026)

• File Making Tax Digital VAT returns straight to HMRC — free for all users, no membership required
• Connect HMRC by secure OAuth and see every open and fulfilled obligation in one place
• Type figures in by hand or import from CSV/Excel, with automatic deadline reminders and instant confirmation emails
• WeFile is HMRC-recognised MTD-compatible software for VAT

Company formation, free or agent-handled (July 2026)

• Incorporate a UK limited company free through the official Companies House XML Gateway, with live name checking, multiple directors, shareholders and share classes
• Or use formation agent mode — £15 agent fee plus the Companies House fee (£100 standard, £156 same-day), with ID verification for AML/KYC and automatic retrieval of your Certificate of Incorporation

Far deeper CT600 coverage

• Property business income (Box 190), chargeable gains (Boxes 210/215/220) and qualifying charitable donations (Box 305)
• Trading losses carried back to the previous period (Boxes 45, 780 and 790)
• Exporter status (Boxes 616/617/618) and principal activity by SIC code
• Bank details for HMRC repayments (Boxes 920–940)
• Associated companies feeding the rate thresholds and marginal relief
• Disallowable expenses added back automatically in the tax computation
• Rebuilt against the latest HMRC CT600 (2026) V3 schema, so capital-allowance submissions no longer trip gateway error 4065
• Coverage now stands at 81 supported boxes across 10 categories, including every CT600A box from A1 to A80

Proper FRS 102 1A accounts notes

• Tangible fixed assets note with a full movements table and a depreciation policy
• Debtors and creditors breakdown notes, including prior-year comparatives
• Custom notes — going concern, related parties, post balance sheet events, dividends — now with real tables, your own column headings and units, automatic totals and subtotal rows
• New balance sheet lines: stocks, provisions for liabilities and called up share capital not paid
• New P&L lines: deferred tax and interest payable and similar charges, both properly XBRL-tagged

Better for accountants and firms

• Agent filing mode — submit under your own Government Gateway credentials with Agent Reference ID and declarant details in the HMRC XML
• Direct amendments to HMRC and Companies House, even where the original return wasn't filed through WeFile
• Manual accounting period entry for when your HMRC period doesn't match the Companies House record
• Real-time dashboards — filings, invoices, tickets and companies update live, with no refreshing
• White-Label Portal — a branded, embeddable filing portal for your own clients
• Trial balance import from Xero, QuickBooks and FreeAgent now maps stock and interest accounts automatically

TinyTax is a browser-based tool that offers free dormant company filing and low-cost CT600 submissions for micro-entities.

Pricing: £20 per dormant filing, £59 per trading company filing, or £99 for a portfolio of 2–3 companies.

Strengths

• Clear, affordable per-filing pricing
• AI-powered trial balance mapping from Excel/CSV
• Can pull prior-year CT600 data from HMRC
• Multi-client dashboard for accountants

Limitations

• Micro-entities only — your company must meet at least two of: turnover under £1m, balance sheet under £500k, fewer than 10 employees
• No API access for developers
• No white-label portal for accountants
• Limited support for complex scenarios

Verdict: A solid free/low-cost option if you qualify as a micro-entity, but you'll outgrow it quickly if your company doesn't meet the thresholds.

TaxPipe positions itself as a simple, one-off filing service — perfect for businesses that file once a year and don't want a recurring subscription.

Pricing: £59 per return (one-time fee).

Strengths

• No subscription commitment
• Guided wizard with plain English explanations
• Automatic iXBRL tagging
• Direct HMRC submission
• Handles marginal relief calculations

Limitations

• £59 per filing — more than double WeFile's £25 trading price
• No Companies House direct submission (generates iXBRL but you submit separately)
• No bulk pricing for accountants
• No API access
• No AI assistance

Verdict: Decent for a one-off annual filing, but at £59 it's expensive compared to WeFile's £25. If you manage multiple companies, the costs add up quickly.

TaxCalc is a well-established, professional-grade tax software suite popular with accountants and tax advisors.

Pricing: From £130/year for a single company (Limited Company Solo 6 plan). Practice licences are priced higher.

Strengths

• Two data entry modes: guided "SimpleStep" and HMRC-form facsimile
• Comprehensive CT600 coverage including all supplementary pages
• Strong validation and error checking
• Cloud and desktop versions
• Companies House filing via dedicated module
• Integrates with TaxCalc Accounts Production

Limitations

• £130+/year — overkill if you're a single company
• Steeper learning curve than wizard-based tools
• Companies House filing requires a separate module
• Designed primarily for tax professionals

Verdict: Excellent for accountants who need deep CT600 coverage and already use the TaxCalc ecosystem. But for a single small company, it's overpriced and overcomplicated compared to WeFile.

TaxFiler offers online accounting and tax software with Corporation Tax filing included in its subscription plans.

Pricing: From £10/month (Startup plan for up to 10 clients) or £20/month (Solo plan for up to 30 clients).

Strengths

• Very competitive monthly pricing
• Covers accounts preparation, corporation tax, VAT, and self-assessment
• Suitable for micro-entities (FRS 105 and FRS 102 1A)
• Integrates with cloud bookkeeping software
• Good for small practices managing a handful of clients

Limitations

• Subscription-based — you pay monthly regardless of filing frequency
• ~£120–240/year depending on plan
• Less well-known with a smaller user community
• Primarily designed for practices, not individual companies

Verdict: TaxFiler is one of the more affordable subscription options, especially for small practices. But if you're a single company filing once a year, WeFile's £25 per filing is still more economical.

The best CT600 filing software depends on your situation:

Choose WeFile if:

• You want the lowest cost per filing with no subscription
• You're a small company (not just micro-entities)
• You're an accountant wanting bulk pricing at £250/year for up to 100 filings
• You're a developer needing API access for automated filings
• You want both HMRC and Companies House filing in one place
• You value a guided, wizard-based experience with AI assistance
• You're a close company with director's loans and need CT600A and s455 handled properly
• You want CT600, Companies House accounts, MTD VAT and company formation under one login
• You need to amend a return that was originally filed somewhere else

Choose TinyTax if:

• You're a micro-entity looking for the cheapest possible option
• You have a dormant company and want a budget-friendly £20 filing
• You manage 2–3 companies and the £99 portfolio deal works for you

Choose TaxPipe if:

• You file once a year and don't mind paying £59
• You want a simple, no-account-needed experience

Choose TaxCalc if:

• You're a tax professional needing comprehensive CT600 coverage
• You need all supplementary pages and deep validation

Choose TaxFiler if:

• You run a small practice and want an affordable monthly subscription
• You need accounts preparation, corporation tax, and VAT in one tool

With HMRC's free filing service closing in March 2026, every UK limited company needs a plan. The market offers everything from budget per-filing tools to professional suites costing hundreds per year.

For the vast majority of small businesses and accountants, WeFile offers the best combination of simplicity, affordability, and power:

• £25 per trading filing — no subscription, no hidden fees
• £15 for dormant companies — cheaper than every competitor
• £250/year accountant membership — file up to 100 companies for as little as £2.50 each
• Both HMRC and Companies House in one workflow
• AI-powered assistance and a guided wizard that anyone can use
• Developer API and White-Label Portal for firms wanting to build on top
• CT600A and s455 on loans to participators, calculated and filed inside the same return
• Free MTD VAT filing and free company formation alongside your CT600

Get started with WeFile today and file your next CT600 in minutes, not hours.

This comparison was last updated on 15 August 2026. Pricing and features are based on publicly available information and may change. WeFile is committed to transparency — if you spot an inaccuracy, please contact us.