Frequently asked questions.
Plain-English answers to the questions UK company directors ask us most. Can't find what you need? Contact support and we respond within one working day.
Getting started
Do I need an accountant to file my company tax?
Not necessarily. If your company is a micro-entity with straightforward finances (one company, simple income and expenses, no complex transactions), you can file your own CT600 and accounts using software like SimpleCompanyTax. The platform guides you through every step in plain English. If your company has complex transactions, associated companies, R&D claims, or you're simply not confident handling it yourself, an accountant is worth the investment.
What is "company tax" in the UK?
When people say "company tax," they usually mean corporation tax, the tax UK limited companies pay on their profits. Your company files a corporation tax return (CT600) to HMRC after each accounting period, reporting its income, expenses, and the tax owed. Corporation tax is charged at 19–25% depending on the profit level.
What is a CT600?
The CT600 is the electronic form UK limited companies use to file their corporation tax return with HMRC. It reports the company's income, deductions, and tax liability for an accounting period. The CT600 must be filed electronically in XML format and accompanied by iXBRL statutory accounts. Every limited company within the charge to corporation tax must file a CT600, even if the company made no profit or is dormant.
What if my company made no money?
You still need to file. Even if your company had zero income, you're required to submit annual accounts to Companies House and (in most cases) a CT600 to HMRC confirming nil profits. No profit means no corporation tax, but missing the filing deadlines still incurs penalties. If your company is genuinely dormant, you may be able to notify HMRC and avoid CT600 filing entirely, but Companies House accounts are still required annually.
What if my company is dormant?
Dormant companies still have filing obligations. You need to file dormant accounts at Companies House annually and may need to file a nil CT600 at HMRC (unless HMRC has confirmed you don't need to). Dormant doesn't mean "nothing to do". If a dormant company misses its deadlines, it faces the same penalties as an active company.
HMRC asked me to file a return where the start and end date are the same day. Is that right?
Yes, this is a one-day "stub" return, and we support it. It usually happens when a company is incorporated on the last day of a month: your first Companies House period runs 12 months plus one day, HMRC caps a Corporation Tax period at 12 months, so a one-day return (for example 31 July 2025 to 31 July 2025) realigns things so your next period starts cleanly on the 1st. Enter the same date in both period fields and file as normal. A stub files to HMRC only (your Companies House accounts are not affected), and most stubs are simply dormant/no-activity returns with your closing balance sheet.
Pricing & payment
How much does SimpleCompanyTax cost?
Two simple prices, per company, per year: £10 for dormant companies (no trading activity in the period) and £25 for trading micro-entities (FRS 105). Both tiers include CT600 generation, iXBRL accounts, direct HMRC + Companies House submission, unlimited revisions, and downloadable documents. No hidden fees, no per-filing charges, no premium add-ons.
Why do you charge two different prices?
Dormant filings and trading micro-entity filings are genuinely different pieces of work: a dormant return has no P&L, no tax computation, no fiscal-year apportionment, and a smaller set of iXBRL tags. Pricing each tier accordingly is fairer (and cheaper for dormant filers) than averaging them into one number.
How can you charge only £10 for dormant filings?
Our focused scope lets us automate 99% of the computation and filing logic for dormant companies and micro-entities. We don't employ accountants to manually review every return, because the software handles validation and compliance checking automatically. By serving two well-defined markets, we build deep automation and pass the savings on.
What if my company was dormant last year and is trading this year?
No problem. You pick the plan that matches this filing year at checkout. Next year you pick again. We don't lock you into a tier.
What payment methods are accepted?
We accept all major credit and debit cards (Visa, Mastercard, Amex) via Stripe. All payments are processed in GBP. We never see or store your card details, because Stripe handles all payment security.
Can I get a refund?
If you're not satisfied with the service, contact support and we'll work with you to resolve the issue.
Eligibility & scope
What types of companies does SimpleCompanyTax support?
UK private limited companies (Ltd) that qualify as micro-entities, including: active trading companies, dormant companies, companies with rental income from UK property (including property-only companies), companies with simple chargeable gains from selling a property or investment, companies with any profit level (all three CT bands with marginal relief), and companies with bank interest, loan relationships, and dividends. We do not support other registered types such as LLPs, PLCs, sole traders or ordinary partnerships. When you add your company we check its type at Companies House and tell you if it is not supported before you enter anything.
Where are the audit exemption options?
You won't see separate audit-exemption questions in the portal. SimpleCompanyTax supports micro-entity accounts that claim audit exemption, so we automatically prepare the accounts as audit exempt under Section 477, confirm that members have not requested an audit under Section 476, and apply the micro-entity provisions of the small companies’ regime. If your company needs an audit or its members have requested one, SimpleCompanyTax is not suitable for that filing.
What companies are NOT supported?
Currently we don't support: companies with associated companies (changes the marginal relief thresholds), R&D tax credit claims, group relief or consolidated accounts, PLCs, LLPs, companies with overseas permanent establishments, short accounting periods (coming soon).
Can I file for an LLP (limited liability partnership)?
No. An LLP does not pay Corporation Tax or file a CT600, so SimpleCompanyTax cannot file for it. An LLP is taxed through its members personally and files an SA800 partnership return to HMRC plus LLP accounts to Companies House instead. You can tell an LLP by its company number, which starts with OC, SO or NC. If you add an LLP, we detect this at Companies House and let you know before you enter anything.
Which accounting periods can I file, and how far back can I go?
We support accounting periods starting on or after 1 April 2015, so you can file the current year as well as overdue returns for earlier years. If your accounting period starts before 1 April 2015, SimpleCompanyTax cannot file it. Please note that HMRC's own filing deadlines and late-filing penalties still apply to overdue returns, and HMRC may not accept a very old period online, so check your filing obligations before you start.
Is SimpleCompanyTax recognised by HMRC?
Yes. SimpleCompanyTax submits CT600 returns directly to HMRC via the Government Gateway Transaction Engine and files accounts with Companies House via the CH API. Production filings are accepted today.
Can I use a loss from a previous year to reduce my Corporation Tax?
Yes. If your company made a trading loss in an earlier year that you haven't used yet, you can set it against this year's trading profit, which lowers the Corporation Tax you owe. In the wizard, open Tax adjustments and enter the figure in "Trading losses brought forward". The live estimate updates and it flows through to your CT600. You can't use more loss than you have trading profit, and any unused amount carries forward again. ("Carried forward" and "brought forward" are the same pot of losses, just seen from different years.) The relief is set against trading profit only, not other income like bank interest. Carrying a loss the other way, back to an earlier profitable year to reclaim tax, works differently. See the loss carry-back question below.
What happens to a loss my company makes this year?
You don't need to do anything special. If your company makes a trading loss this year, SimpleCompanyTax reports it on your CT600 and it's carried forward automatically, ready to set against your profits in a future year. There's no Corporation Tax to pay on a loss-making year.
Where do I find my losses carried forward for next year’s return?
In your tax computation, not on your CT600. Every filing we produce ends with a section headed "Losses carried forward to the next period", listing any trading losses, UK property business losses and capital losses the company still has available. Those are the figures to enter next year. Do not read them off the CT600 loss boxes (780, 805 and 825), because those boxes are headed "amount arising" and report what happened in that period rather than the running total you still have. The two are different whenever you used part of a loss or brought one forward, which is most of the time. If you filed with us, open the tax computation PDF in your filing record.
Some of my property losses are from before April 2020. Does that matter?
Yes, and we ask about it separately. Before 6 April 2020 companies paid Income Tax rather than Corporation Tax on UK property income, and losses left over from that era can only reduce property profits. They cannot touch trading profit or bank interest, unlike newer property losses which can reduce your total profits. So if part of your brought-forward property pool is that old, enter that part in "Property losses that arose before 6 April 2020" as well as in the total. It is a portion of the same pool, not an extra amount. We use the older, more restricted losses first, which is what HMRC requires and also leaves you with the more flexible losses to carry forward.
My company made a loss but paid tax last year. Can I claim a refund by carrying the loss back?
Possibly. If your company was profitable and paid Corporation Tax last year, you may be able to carry this year's loss back against that profit and reclaim some of the tax (loss carry-back). SimpleCompanyTax does not file the carry-back claim itself. You make that separately with HMRC, usually by amending last year's return or in writing, normally within two years of the end of the loss-making accounting period. What you can do in SimpleCompanyTax is show the expected refund in your accounts: on a loss-making period, open Tax adjustments and enter the amount under "Expected Corporation Tax repayment". It then appears as "Corporation Tax recoverable" on your balance sheet and as a tax credit in your profit & loss, so your filed accounts reflect what you're owed. Note that a loss on its own does not mean a refund. You only get money back if there was Corporation Tax actually paid in the earlier year that the loss can be set against.
The filing process
How long does the filing process take?
Most micro-entity directors complete everything in 15–30 minutes. Dormant companies are faster, often under 10 minutes.
Can I save my progress?
Yes. Your data is saved automatically as you go. You can close the browser and return at any time.
What if I make a mistake?
You can regenerate your documents as many times as you need. Before final submission, nothing is sent to HMRC.
My filing was stopped before it was sent. What does that mean?
It means we caught a problem HMRC would have rejected, so we did not send the return. Before transmitting anything we check your CT600 against HMRC’s own published validation rules, the same rule set their gateway applies. If the return would fail, we stop and tell you which figure is wrong. Nothing was filed, so there is nothing to withdraw and you are not charged again to resubmit. Go back to the wizard, correct the figure and file again. Your documents are still generated and still in your account if you want to look at the number in context. Being stopped this way is unusual, so if it happens on figures you believe are right, contact support with your filing reference.
Where do I enter entertaining, fines and other disallowable expenses?
In both places. Leave the cost in your expense figures (it's a real business cost, so your accounts must show it) and enter the same amount in the "Disallowable expenses" field in the Tax adjustments section. We add it back when calculating your taxable profit, so your accounts stay accurate and your Corporation Tax is right. A £1,000 fine, for example, goes in your admin expenses AND as £1,000 in Disallowable expenses. Entering it in only one place either understates your tax (expenses only) or overstates both your profit and your tax (disallowables only). This applies to companies of every size, including micro-entities.
Where do I enter a balancing charge for an asset I sold?
In two places, both in the financial inputs. If selling the asset produced a profit in your accounts, open the profit and loss section and select "Add a profit on selling equipment or another fixed asset", then enter that profit. It shows as Other income and is kept out of your taxable trading profit. That also opens the "Balancing charges" field in Tax adjustments (box 710), where you enter the balancing charge, which is your sale proceeds capped at what the asset originally cost. We add the balancing charge to your taxable profit and file it in box 710. One important limit: if you sold the asset for more than it originally cost, the amount above cost is a capital gain, not a balancing charge. If the gain is taxable (everyday items sold for £6,000 or less are exempt), enter it in the "Chargeable gains (gross)" field in Tax adjustments and we report it in boxes 210 to 220.
My company gets rental income from property. How do I enter it?
We support rental income from UK property. In the profit and loss section, select "Add income from property (rent)" and enter one net figure: rent received minus allowable letting costs (agent fees, repairs, insurance, service charges, and interest on a mortgage or loan for the property). Include property-loan interest in that net figure, not in the Interest payable field, or the relief would be counted twice. We report the figure in box 190 of the CT600 and show it as Income from property in your accounts. If the letting made a loss, use the +/− toggle to enter a negative figure and we apply the property-loss rules (box 250) automatically, including losses brought forward from earlier years. If the company sold a property at a profit, that is a chargeable gain rather than rental income. Enter it in the "Chargeable gains (gross)" field. See the capital gains question below.
My company sold a property or investment at a profit. Can I file the gain?
Yes, for simple gains. A company selling a property, shares or another investment at a profit has a chargeable gain, taxed through boxes 210 to 220 of the CT600. You work out the gain (sale proceeds less costs of sale, less what you paid including buying costs, less any improvement costs, less indexation allowance for assets owned before December 2017) and enter it in "Chargeable gains (gross)" behind the "Add a capital gain" link in Tax adjustments. Enter losses on this year's disposals and any unused losses from earlier years in the two fields below it. We set both against your gains automatically, report the net gain, add it to your taxable profits, and show any unused losses in your tax computation for next year. Enter the accounting profit on the sale separately in "Profit on disposal of fixed assets" so your accounts stay right. Some disposals still need an accountant: sales to connected parties, share sales that may be exempt, ATED-related or non-resident gains.
Our company owns property and UK listed shares. Can you file our return?
Usually yes. Rent goes in box 190, dividends received are exempt but still count towards the profits that decide your tax rate (box 620), a sale at a profit is a chargeable gain in boxes 210 to 220, and shares you still hold go in the Investments line on the balance sheet. Two things decide whether we are the right fit. First, the micro-entity size limits: you need to meet two of turnover £632,000 or less, balance sheet total £316,000 or less, and 10 employees or fewer, and a company owning property outright often exceeds the balance sheet limit. Second, FRS 105 carries everything at cost, so if you need the property or the shares shown at market value you need FRS 102 accounts and an accountant. You also work out any gain yourself, including the share pooling rules for a portfolio.
Can we show our investment property or shares at market value?
Not in the accounts we produce. We file micro-entity accounts under FRS 105, which does not permit revaluation or fair value accounting at all: investment property is carried at cost less depreciation and impairment, and investments at cost less impairment. Enter what the company paid, not the current market price. If you need fair value, that requires FRS 102 Section 1A accounts, which we do not produce, so you would need an accountant. It is worth deciding this early because it changes the figures on your balance sheet rather than just how they are presented.
Where do company running costs go if the company has no trade?
It depends what the cost relates to, and the distinction matters because different costs can be set against different income. Costs of letting a property are deducted inside your net property figure before it reaches box 190. Costs of a trade sit in cost of sales and administrative expenses. Costs of managing investments are a separate category in law (expenses of management of an investment business, CTA 2009 s.1219) and are deducted from total profits. A cost cannot be counted twice: letting costs already netted against rent cannot also be claimed as management expenses, and capital costs never qualify. If your company holds investments and its running costs are genuinely costs of managing them, contact us before filing so we can check the treatment with you.
The company received dividends from another company. Are they taxed?
No. Dividends your company receives are exempt from Corporation Tax, so no tax is charged on them and they do not appear in your taxable profits. They do affect the RATE though. HMRC adds exempt dividends to your taxable profits to work out which Corporation Tax band applies (called augmented profits), so a company with £40,000 of profit and £30,000 of dividends is treated as a marginal-relief company rather than a 19% small-profits one, even though the dividends themselves are never taxed. Enter the figure in "Dividends received" in the profit and loss section and we report it in box 620 and apply the rate rules automatically. One limit: dividends from a company yours controls, or that controls yours, are excluded from this calculation, and we do not support group companies at all.
What formats do you deliver?
CT600 XML (for HMRC), iXBRL XHTML (for Companies House and HMRC), and a tax computation (PDF and XHTML). All downloadable from your account.
My first accounting period is longer than 12 months. What do I do?
That's normal for a first year. A CT600 (your Corporation Tax return to HMRC) can only cover up to 12 months, so a first period over 12 months means two CT600s to HMRC, one for the first 12 months and one for the remaining days, while Companies House still gets a single set of accounts covering the whole period. You don't have to work this out or create a second return: SimpleCompanyTax detects the long first period, splits your figures across the two returns automatically, and files one set of accounts plus both CT600s.
Do you file to both HMRC and Companies House?
Yes, and you choose what to file. On the final filing screen you can send both at once, or pick just one: the CT600 to HMRC, or the annual accounts to Companies House. Both targets are ticked by default, so untick one to file only the other.
I’ve already filed my accounts to Companies House. Can I file just the CT600 to HMRC?
Yes. On the filing screen, untick Companies House so only HMRC is selected, then submit. The button changes to “Submit to HMRC” and you only enter your HMRC credentials. This works whether your accounts were filed through us or elsewhere (for example by an accountant). From your company page you can also use the “File CT600” action, which opens the filing screen with HMRC already selected.
Can I file only my accounts to Companies House (not the CT600)?
Yes. Untick HMRC on the filing screen so only Companies House is selected, then submit. The button changes to “Submit to Companies House” and you only enter your Companies House authentication code. (Most companies still need to file a CT600 to HMRC as well, so only do this if your CT600 is already filed or not yet due.)
I don't have a Government Gateway account set up for Corporation Tax. How do I create one?
To file a CT600 you need a Government Gateway account that is enrolled for Corporation Tax for that specific company, and HMRC recommends a separate Government Gateway ID for each company you run. To set one up, go to gov.uk/log-in-register-hmrc-online-services, choose Sign in then "Create sign in details", say No to being an agent and Yes to accessing services as a business, and set up the new ID. Once signed in, choose to add Corporation Tax and enter the company's UTR and Company Registration Number (or registered postcode). HMRC then posts an activation code to your registered office, usually within about ten working days, and you sign back in and enter it to link your UTR. Because of that postal delay, set this up well before your deadline rather than on the day you file.
What credentials do I need to submit, and where can I find them?
You will be asked to enter your credentials at the final step, immediately before filing.
For Companies House (statutory accounts filing):
You will need your company's 6-character Companies House authentication code. This code is sent by post to your registered office address. If you do not have it, you can sign in to Companies House WebFiling and select “Request an authentication code”. A replacement code is typically delivered to the registered office within five working days.
For HMRC (Corporation Tax return filing):
You will need:
- Your company's 10-digit Corporation Tax Unique Taxpayer Reference (UTR)
- The Government Gateway user ID and password for an account that is enrolled for Corporation Tax for the company
Your Corporation Tax UTR can be found on HMRC Corporation Tax correspondence or within your Business Tax Account. If you have forgotten your Government Gateway user ID, you can recover it through the HMRC online services portal.
For security, your credentials are used only for this submission and are never stored. Your Government Gateway details and your Companies House authentication code are both transmitted for the filing and then discarded. You re-enter them next time you file.
After you file & paying HMRC
I made a mistake on a return I already filed. Can I correct it?
Yes. Open the accepted filing and choose "Amend this filing". We pre-fill your accepted figures, you change what needs correcting, briefly note what was wrong, and we submit an amendment to HMRC and, if your accounts are affected, revised accounts to Companies House. HMRC accepts amendments up to 24 months after the end of the accounting period (12 months after the filing deadline). Revised accounts to Companies House have no equivalent deadline. Amendments are included free with an active subscription. If your original return was rejected rather than accepted, there is nothing to amend. Just fix the problem and file again.
When will my Corporation Tax show in my HMRC account after I file?
Once HMRC accepts your CT600, the amount you owe is posted to your company's Business Tax Account under "View your Corporation Tax", usually within a few working days of acceptance, often within a day or two and occasionally longer at busy times. HMRC doesn't publish a guaranteed timescale, so treat "a few working days" as the expectation. Your acceptance receipt from SimpleCompanyTax already shows the tax figure, so you don't have to wait for the online account to update.
Can I pay HMRC before the amount shows in my account?
Yes, and you often should. Corporation Tax is self-assessed, so you can pay as soon as you know the figure (your filing receipt shows it) without waiting for the portal to update. As long as you use the correct 17-character payment reference for the accounting period, HMRC matches your payment to the right period. This matters because the deadline to pay is earlier than the deadline to file.
Do I need to choose the accounting period when I pay?
Effectively yes, and you do it through the payment reference. There isn't a separate "which year?" step. The 17-character reference is how HMRC knows which accounting period your money belongs to. Use the reference for the period you're paying and the payment lands against that period. Paying the right amount with the wrong period's reference is the most common mistake.
Is my Corporation Tax payment reference the same every year?
No. The 17-character payment reference is your fixed 10-digit UTR plus a suffix that identifies the specific accounting period (for example 1234567890A00108A). Your UTR stays the same, but the full reference is different for every accounting period, so don't reuse last year's. You'll find the correct one on HMRC's payment reminder/payslip or in your HMRC online account when you select the period to pay.
How do most people pay their Corporation Tax, and by when?
Most companies file first to lock in the exact figure, then pay HMRC directly soon after, usually by Faster Payments bank transfer because it's quick and free, using that period's 17-character reference, without waiting for the online balance to catch up. Payment is due 9 months and 1 day after the end of the accounting period (the CT600 itself is due 12 months after), so the tax is usually payable before the return is due. SimpleCompanyTax files your return but does not collect the tax. You pay HMRC directly.
How do I tell HMRC this is my final CT600 because the company has stopped trading?
There is no "final return" box on the CT600. You file a final CT600 with the accounting period ending on the date the company stopped trading, then separately tell HMRC the company is now dormant. If you are closing it instead, apply to strike it off at Companies House (form DS01). Filing the CT600 on its own does not stop future returns: HMRC keeps expecting one until the company is made dormant or dissolved. Your Corporation Tax period can be shorter than your Companies House period, which is normal and accepted by HMRC.
Data & security
Where is my data stored?
On managed UK cloud infrastructure. Data is encrypted at rest (AES-256) and in transit (TLS 1.2+).
Can I delete my data?
Yes. You can delete your account and associated data at any time, subject to statutory record-keeping requirements (financial records are retained for up to 6 years under UK law).
Do you sell my data?
No. Never. Our Privacy Policy sets out exactly how we process and share data.
Still have a question?
Support responds within one working day, sooner if your filing deadline is close.