Guides
Plain-English answers to company tax questions. Checked against HMRC, updated when the rules change.
What expenses can my company claim against Corporation Tax?
Which business costs cut your tax, the bits people get wrong, and what we sort for you.
Read the guide →Corporation Tax basics
8 guidesWhat is Corporation Tax and how does it work?
The plain-English starting point: what the tax is, whether your company owes it, and the yearly cycle.
How is Corporation Tax actually worked out?
A real worked example in pounds, showing how your bill is calculated.
Why do I owe tax when my accounts show almost no profit?
Taxable profit isn't the same as accounting profit, here's why the two differ.
Do I pay Corporation Tax if my company made no profit (or a loss)?
No profit means no tax, but you still file, and a loss can cut a future bill.
What's the Corporation Tax rate for a small company?
The two main rates, the band in between, and what marginal relief means for you.
Corporation Tax vs the tax you pay yourself (salary and dividends)
How the company's tax differs from the tax on what you take out as salary or dividends.
What records do I need to keep for Corporation Tax?
What to keep, the six-year rule from your year-end, and the £3,000 fine if you don't.
Companies House vs HMRC: what's the difference and what do I send each?
Two bodies, two filings: accounts and a confirmation statement to one, your tax return to the other.
Allowable vs disallowable expenses
8 guidesWhat expenses can my company claim against Corporation Tax?
Which business costs cut your tax, the bits people get wrong, and what we sort for you.
Can I claim my laptop, van or equipment?
Capital allowances and the £1m Annual Investment Allowance, with no jargon.
Can my company claim travel, mileage and parking?
Work travel and driving your own car at 55p a mile, the commute trap, and why fines never count.
Can my company claim working-from-home costs?
The safe £6 a week, and the household-bill mistake that lands you a personal tax bill.
Can my company claim my mobile phone and broadband?
One company-name phone is tax-free, and the personal-contract trap that costs you tax.
Can my company claim food, drink and entertaining?
Client lunches the company can pay but don't cut tax, your everyday lunch is out, and a staff do does.
Can my company pay me a salary, and is it tax-deductible?
When your salary counts as a business cost, and how it differs from dividends.
What records do I need to keep to claim expenses?
What to hold onto, and the six-year rule for keeping your company records.
Deadlines and penalties
6 guidesEvery Corporation Tax deadline (and what happens if you are late)
The 9-month, 12-month and 9-months-and-a-day rules, and the exact late fines.
What happens if I file my Company Tax Return late?
The exact penalties in pounds, including the £200 day-one charge from April 2026.
Companies House late-accounts penalties: the exact £ amounts
How much late accounts cost at Companies House, up to £1,500.
First-year deadlines: why your first accounts are different
The 21-months-from-incorporation rule and why year one isn't like the rest.
I've already missed a deadline, what do I do?
Appeals, reasonable excuse, and the calm next step if you're already late.
What's a confirmation statement, and do I have to file one too?
The yearly confirmation statement explained, and whether it applies to you.
Filing and the CT600
8 guidesHow do I file my Company Tax Return?
The five steps start to finish: accounts, the tax, the CT600, sending it to HMRC, and paying.
What is a CT600, and do I need to file one?
What the CT600 form is, and whether your company has to send one.
Can I file my own CT600? (yes, here's what's involved)
Exactly what filing your own return involves, step by step.
Is it safe to file my own Corporation Tax?
The honest answer, plus when getting help is the right call.
What you need before you file: accounts, computations, iXBRL
The pieces you need ready before filing, in plain English.
Filing accounts AND a CT600: why it's two filings to two places
Why HMRC and Companies House each need their own filing.
What it costs to file yourself vs an accountant
£99 once vs £600, £1,800 a year, a straight comparison.
What is iXBRL tagging, and why does HMRC want it?
What iXBRL is, why HMRC asks for it, and why you don't do it by hand.
Specific situations
6 guidesDo I need to file a Company Tax Return?
A plain yes or no, whether you made a loss, earned nothing, or are dormant.
My company is dormant, what (if anything) do I file?
What a dormant company actually has to send, and to whom, and why it never means file nothing.
What's a director's loan, and why does it affect my tax?
The overdrawn director's loan account, the 33.75% charge, and the £10,000 trap, explained simply.
First year of trading: what your first return covers
Your first year, why it runs past 12 months, and the two-return quirk that catches new companies out.
My company rents out property, how is that taxed?
How rental income is taxed when your company is a landlord.
What's an "accounting period" and why might I have two?
What an accounting period is, and when a company ends up with two.
FRS 105 / micro-entity accounts
4 guidesWhat is FRS 105? Micro-entity accounts in plain English
The simplest accounting standard for the smallest companies, explained.
Does my company count as a micro-entity?
The size tests with £ thresholds, so you can tell if you qualify.
FRS 105 vs FRS 102, which one is my company?
How to tell which accounting standard applies to your company.
What actually goes in a micro-entity balance sheet and P&L?
What a micro-entity balance sheet and profit and loss account contain.
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