PAY WHAT YOU OWE. NOT A PENNY MORE.
Corporate Tax Returns and Compliance
The year has been lived. The work has been done. Customers served, decisions made, challenges navigated, and bills settled. And then quietly,
reliably, without announcement a new obligation arrives. The company tax return. The moment when everything the business earned and spent in the
past twelve months is translated into the language of tax law — and handed to HMRC with a declaration that it is correct. This page is about what that
process really involves, why it deserves more than a rushed submission, and what it feels like when it is handled by people who genuinely know what they
are doing.
THE QUIET ARRIVAL OF TAX SEASON
Corporation tax does not shout. It simply waits, and then it is suddenly urgent
There is a particular quality to the way corporation tax arrives in a director’s life. It does not impose itself through the year in the way that other responsibilities do. It does not ring at inconvenient moments or send reminders during busy weeks. It simply sits — somewhere in the background, behind the orders and the meetings and the cash flow decisions — and waits for its turn.
And then the year ends. The turn arrives. For some directors, this moment feels entirely manageable. They have good records, a clear picture of the year, and a reliable team to handle the preparation. For others, it arrives with a familiar undertow of uncertainty. Not panic, exactly. More a quiet but persistent question: have we got this right?
Is the tax position correctly calculated? Are there reliefs or claims the company should be making but is not? Are there adjustments that need to be applied before the return can be filed with confidence? Is there anything in the return that, if HMRC looked closely, would require a difficult conversation?
These are not neurotic questions. They are the reasonable concerns of a responsible director who understands that corporation tax is consequential that errors have costs, and that the rules governing it do not always behave the way common sense might suggest.
Corporation tax compliance is not simply about meeting a deadline. It is about filing a return that is accurate, defensible, and built on work that has been done properly from the very beginning.
THE FUNDAMENTAL DISTINCTION
Accounting Profit vs Taxable Profit: Understanding the Difference
This is the central concept in corporate tax compliance, and it is one that causes more confusion and more costly errors than almost any other single misunderstanding in the field. We want to be very clear about it.
When a company’s annual accounts are finalised, they show an accounting profit a figure calculated in accordance with accounting standards, reflecting the economic reality of the year. This figure is the starting point for the corporation tax return. But it is only the starting point.
Tax law then applies a distinct set of rules to that accounting profit adjustments that can push the taxable profit significantly higher or lower than the accounting figure. Some expenses that are entirely legitimate in the accounts are not permitted as deductions against taxable profits. Some capital purchases that appear as assets in the accounts attract capital allowances a tax-specific mechanism that can allow relief in a different pattern from the accounting depreciation. Losses from earlier years may be available to offset against current profits. Research and development expenditure, if it qualifies, can attract enhanced relief.
The document that records all of these adjustments — moving from accounting profit to taxable profit — is called the tax computation. It is the working document that sits behind the corporation tax return, showing every adjustment, every claim, every relief, and precisely how the final taxable figure was arrived at. A well-prepared tax computation is the evidence that the return is correct. It is also the document that protects the company if HMRC ever
decides to look more closely.
This page is specifically about the tax computation and the return that flows from it. The annual accounts that provide the starting point are covered on their own dedicated page, where they receive the full treatment they deserve as a separate and distinct professional obligation.
ADJUSTMENT ONE
Disallowable expenses
Certain costs in the accounts — client entertainment, some fines and penalties, and depreciation itself — are added back to the accounting profit for tax purposes. The company has genuinely spent the money. But HMRC does not permit them as tax deductions. Missing these add-backs
understates the taxable profit and creates a compliance risk.
ADJUSTMENT TWO
Capital allowances
When a company buys qualifying assets, the accounting treatment spreads the cost as depreciation. The tax treatment uses capital allowances instead, and in some cases the entire cost can be deducted in the year of purchase. Failing to claim capital allowances means paying more tax than the company is legally required to pay.
ADJUSTMENT THREE
Loss relief
If the company has made losses in previous years or in the current year, those losses may be available to offset against taxable profits. Loss relief is not automatic. It requires a claim, and the right conditions must be present. Losses that are not claimed are wasted relief that can never be recovered.
ADJUSTMENT FOUR
Other reliefs and claims
Depending on the nature of the business, there may be additional claims available, research and development relief for innovative companies, or deductions for specific types of qualifying expenditure. These reliefs exist because Parliament created them. Companies that qualify and do not claim them are simply leaving money on the table.
Marcus, and the capital allowance nobody mentioned
Marcus had been running his small printing business for nine years. He was meticulous about most things — his production quality, his client relationships, his delivery times. His accounts were prepared each year by a firm he had used since the beginning. The returns were filed on time. The tax was paid. He had no reason to think anything was wrong.
In his seventh year, Marcus invested in a significant piece of new equipment. It was expensive and meaningful purchase for a business of his size but it transformed his capacity. He recorded it correctly as a fixed asset and paid the full tax bill that year without question.
When Marcus came to us, one of the first things we did was review his recent tax history. The capital allowances position stood out immediately. The annual investment allowance, which in the year of his equipment purchase had been at a level that would have allowed the full cost to be deducted against taxable profits in that year, had not been claimed. The tax had been calculated on a profit figure that should have been considerably lower.
His previous firm had not done anything dishonest. They had simply not noticed. The return had been filed, the tax had been paid, and the opportunity had passed — quietly, without anyone realising it had been there. We made very sure that Marcus understood every capital allowance available to him going forward, and that none of them would ever be missed again.
THE COMPLIANCE FRAMEWORK
What a company must do, when it must do it, and what happens when obligations are missed
Every UK limited company that is trading — or that has income, or that has recently ceased has corporation tax obligations. These are not discretionary. They are statutory requirements enforced by HMRC, with a penalty structure that escalates the longer obligations remain unmet.
The annual filing of the corporation tax return, known formally as a CT600, must be submitted within twelve months of the end of the accounting period. But the payment of any tax due must be made within nine months and one day of the year-end, importantly, before the filing deadline.
Two clocks running at different speeds
Most directors know there is a filing deadline. Many assume the payment is due at the same time. In fact, there are two separate clocks, one for filing, one for payment, and they run at different speeds. The payment clock runs faster. A company that waits until the return is fully prepared before thinking about payment may find that interest has already been accruing quietly, automatically, from the date the payment was due. Understanding this distinction, and planning around it, is one of the most straightforward ways to avoid unnecessary charges.
Compliance as scaffolding, not ceiling
Some directors think of tax compliance as a ceiling — the maximum obligation, the thing that must be endured and got over with. We think of it differently. Compliance is scaffolding. It is the structure that holds everything else up that creates the conditions under which the company can operate confidently, borrow when needed, and grow without fear of a compliance issue surfacing at the worst possible moment. The company that is fully compliant has options. The company that is behind on its obligations is always slightly constrained.
THE EXPENSES QUESTION
What is allowable for tax, what is not, and why it is more nuanced than most directors expect
One of the questions we hear most often from directors — usually accompanied by a slightly apologetic expression, as though they feel they should already know the answer — is some version of: can I claim this?
It is a perfectly reasonable question. And the honest answer, more often than they expect, is: it depends. Not because tax advisers enjoy being vague — but because the allowability of an expense for corporation tax genuinely depends on the specific facts surrounding it. The nature of the expense. How it was used. Whether it has any personal element. Whether it falls within a category that HMRC has specifically addressed.
The general principle is that expenses incurred wholly and exclusively for the purposes of the trade are deductible against taxable profits. That phrase wholly and exclusively sounds clean and clear. In practice, it generates a substantial body of case law, because the line between business and personal, between wholly and partially, is not always obvious from the outside.
A home office. A vehicle used for both business and personal journeys. A meal with a client that turns into dinner with a friend. Each of these sits somewhere on a spectrum, and the right tax treatment requires judgment rather than a mechanical rule. We apply that judgment carefully ensuring that every legitimate deduction is claimed, every disallowable item is correctly identified, and the company’s tax position is both as efficient as the rules permit and as defensible as scrutiny might require.
Amira, and the mixed-use question she had been sitting on for three years
Amira ran a small architecture practice. She was thoughtful, precise, and very good at her work — qualities that extended, mostly, to her financial management. But there was one area of her tax position she had never quite resolved: her car. She used a single vehicle for both her practice and her personal life. She knew there were rules. But the rules, as she understood them, were simultaneously simple in principle and unclear in application.
For three years, she had been claiming a figure she had arrived at through a combination of rough estimation and what felt like reasonable caution, deliberately conservative to avoid any risk of overclaiming. When we reviewed her position, we found that her caution had been costing her real money every quarter. The rules permit a specific and structured approach to claiming business mileage, and the figure she had been entitled to claim was meaningfully higher than the one she had been submitting.
She had not been doing anything wrong. She had been trying to be careful. But caution applied without knowledge is not really caution, it is just leaving money on the table with extra anxiety attached. We set up a simple mileage record, applied the correct method, and made sure her tax position from that point forward reflected what she was actually entitled to.
PLANNING AHEAD NOT JUST FILING BEHIND
Proactive Corporation Tax Planning: How to Reduce Your Tax Bill Before Year-End
There is a version of corporation tax compliance that is purely retrospective. The year ends. The accounts are prepared. The tax computation is run. The bill arrives. The director pays it and returns to running the business. This version is not wrong. But it misses something valuable.
Corporation tax, unlike many financial obligations, is something that can be thought about before the year ends. Not in the sense of anything improper the tax owed on genuine profits is owed, and the job of a reputable adviser is never to pretend otherwise. But in the sense of understanding, during the year, what the likely tax position will be and making legitimate decisions in light of that understanding.
A director who knows in October that the company is heading for a strong profit year can make decisions about timing of certain expenditures, investment in qualifying assets, or pension contributions that are entirely legitimate and that can materially affect the tax position. The same director who only discovers what the tax bill will be the following spring has lost the window to act the year is closed, the decisions are made, and the only remaining question is how much to pay.
George - the pension contribution and the timing that made the difference
George ran a successful consultancy. By the autumn of his fifth trading year, it was clear the company had had a strong year significantly better than the previous two. His profit was going to be meaningfully higher than it had been for some time.
George was in his mid-fifties and had been meaning, for several years, to increase his pension contributions. He had not yet done so not because of reluctance, but because life had been busy and the right moment had not presented itself clearly enough.
We spoke in November. We went through the likely year-end position together what the profit looked like, what the tax bill was trending towards, what the available options were. One of those options was a company pension contribution before the year end. It was a decision George had already been intending to make. The question was simply when.
Making the contribution before the year end meant it fell into the current tax year. The corporation tax relief on a qualifying pension contribution is real and immediate a reduction in the taxable profit in the year the contribution is made. The saving was not trivial. And because George had already decided he wanted to make the contribution, there was nothing artificial about it — it was simply a matter of acting within the year rather than after it. He told us later that the November conversation had been worth considerably more than an April one would have been. By April, the year was over. In November, there was still time.
WHEN HMRC LOOKS CLOSELY
HMRC Enquiries into Corporation Tax Returns: What to Expect and How to Prepare
HMRC has the right to open an enquiry into any company’s corporation tax return within a certain period of its filing. Enquiries can be triggered by specific risk factors, unusual figures, significant year-on-year changes, industry benchmarking, or they can be opened at random. Most businesses will never experience a formal enquiry. But some will.
When an enquiry is opened, HMRC asks questions. It wants to understand the basis for the figures in the return. It may ask for supporting records, explanations of specific transactions, or evidence that a claimed relief genuinely applies. The process can be brief and straightforward — or, if the return was not well prepared and the underlying records are not in good order, it can become protracted and expensive.
The best protection against an enquiry becoming a problem is not luck. It is preparation. A return prepared carefully, from a tax computation that clearly shows the reasoning behind every adjustment, is a return that can answer HMRC’s questions clearly and confidently. There is nothing to hide, because nothing was hidden. There is nothing to correct, because nothing was wrong.
The return that can speak for itself
Imagine a well-organised filing cabinet. Every document is where it should be. Every transaction has a record. Every claim has its supporting evidence. When someone opens a drawer and asks a question, the answer is already there, clear, accessible, and complete. A well-prepared corporation tax return is that filing cabinet. It does not need to be defended because it is already defensible. The work that goes into preparing it properly is what makes any scrutiny a minor inconvenience rather than a significant ordeal.
DIRECTORS AND THEIR COMPANY
The tax relationship between a company and the people who run it
For many small limited companies, the director and the company are almost the same person in a practical sense — the same human being, wearing two different legal hats. But in the eyes of tax law, the company and its directors are entirely separate entities. The company pays corporation tax on its profits. The director pays personal tax on money taken out of the company — whether as salary, dividends, or other forms of remuneration.
This separation creates a relationship between the company’s tax position and the director’s personal tax position that runs in both directions. How the company structures its remuneration affects both its own corporation tax liability and the director’s personal tax bill. Dividends paid to directors who are also shareholders interact with the corporation tax position in ways that require proper understanding.
The director loan account — the running balance of money flowing between the company and its directors — has specific tax rules that apply when it sits in certain positions at the company’s year-end. Getting this wrong is an entirely avoidable complication that we see arise regularly when the company’s affairs and the director’s affairs have not been considered together.
The director’s personal self-assessment return, which handles the personal tax side of this relationship, has its own dedicated page on this website. What matters here is simply the awareness that the company’s corporation tax position and the director’s personal tax position are part of the same picture. Decisions made on one side without considering the other can produce entirely preventable consequences.
OUR APPROACH
How we handle corporate tax work because process and outcome are inseparable
We want to describe how we actually work, because we think it differs from what many directors have experienced elsewhere.
We begin every corporation tax engagement by understanding the company — not just the numbers, but the business itself. What it does, how it earns its money, what kinds of costs it incurs, what happened in the year that might have tax significance. This understanding is not background colour. It is the foundation on which good tax work is built. A tax computation prepared without this understanding is a set of numbers moving through a process. A tax
computation prepared with it is a reflection of a real business, properly understood.
From that understanding, we work through the figures and identify every adjustment required to move from accounting profit to taxable profit. We consider every category of potentially disallowable expenditure. We review the capital expenditure for the year and assess the capital allowances position fully. We consider whether any reliefs — loss relief, R&D if applicable, any others — are available and should be claimed. We look at the director loan
account position at year-end. We check for internal consistency throughout the computation.
When the computation is complete, we do not simply file it. We go through it with the client in plain language, with the clear intention that the director understands what is being filed in their company’s name. A director who signs off on a corporation tax return should understand it. Not at the level of every technical nuance, but at the level of: this is the profit the company made, these are the adjustments applied, this is the tax that results, and this is why.
Review before preparation
We look at the tax position before we start preparing the return, not after. Issues identified early can be addressed properly. Issues
discovered during filing creates pressure that leads to compromises in quality.
Computation before submission
The detailed tax computation is prepared, checked for consistency, and reviewed against the accounts before anything is filed with HMRC. The submission is the last step, not the first.
Explanation before sign-off
Every director we work with receives a clear explanation of what the return shows and why the tax figure is what it is. We do not file on behalf of clients who do not understand what they are filing.
Availability throughout the year
We do not disappear between filings. We stay available for planning conversations that arise during the year, because the most useful tax
advice is often the kind that arrives when decisions can still be shaped by it.
Explore Related Services
How This Service Fits Into Your Wider Financial Framework
Corporation tax is one component of a company’s wider financial and compliance structure. To operate efficiently and remain fully aligned with HMRC requirements, it needs to work in coordination with several other core areas of your business.
Your financial reporting typically begins with statutory accounts, which establish the accounting position and form the foundation for tax computations. Alongside this, directors and shareholders may have personal tax responsibilities that arise from company income, requiring careful alignment between business and individual tax planning.
Operational areas such as VAT, payroll, and bookkeeping also play a critical role. These functions run continuously throughout the year, feeding into the overall financial position and ensuring that records remain accurate, compliant, and ready for reporting.
For new or growing businesses, company formation and structuring decisions further influence how tax obligations are managed and optimised over time.
Each of these areas serves a distinct purpose, but together they form a cohesive financial system. When managed in an integrated way, they provide clarity, control, and a stronger foundation for decision-making.
FOR THE DIRECTOR READING THIS
You are responsible for the company. The tax side should be something you can trust completely
Being a director of a limited company comes with responsibilities that are both rewarding and genuinely weighty. You are accountable to HMRC, to Companies House, to any shareholders, and ultimately to yourself, for the compliance position of the company you lead. That accountability does not end with good intentions. It extends to the actual accuracy of what is filed, the actual timeliness of what is paid, and the actual quality of the work that
sits behind both.
We work with directors who take that accountability seriously. Those who do not want to be told everything is fine without understanding why it is fine. Who wants to see the work, understand the reasoning, and know with genuine confidence rather than wishful thinking, that the tax side of their company is being handled correctly.
We also work with directors who have, for whatever reason, found themselves behind. Returns not filed. Payments missed. A growing unease about the gap between where the company’s obligations stand and where they should be. We do not judge this. We have seen it many times, and the route back to full compliance while it requires work and sometimes requires direct conversations with HMRC — is almost always navigable. The most important step is deciding to take it.
Wherever your company’s tax position currently stands, well in hand, slightly uncertain, or in genuine need of attention, we are here to help move it to a place that feels right. Properly filed. Correctly calculated. Clearly understood. And ready for whatever the next year brings.
Let us handle the company tax properly
Whether your year-end is approaching, your return is due, your position needs reviewing, or you simply want a more attentive team in your corner for the tax side of the business, we would welcome the conversation.
We will talk through where the company stands, what the tax obligations look like, and what working together would involve. No obligation, no pressure. Just an honest discussion between people who understand that getting this right matters.
The Contact page is the place to start. We look forward to hearing about your company — and to making sure its tax affairs are exactly as they should be.
FAQs about Corporate Tax Returns and Compliance
Corporate Tax Returns and Compliance
For most small companies, corporation tax is due nine months and one day after the end of your accounting period. Missing the deadline results in interest charges and penalties that escalate quickly.
What is the current rate of corporation tax and how is it calculated?
The main rate of corporation tax is 25% for companies with profits over £250,000, with a small profits rate of 19% for profits up to £50,000. Companies in between may qualify for marginal relief — we calculate exactly what you owe.
What expenses can my company deduct to reduce its taxable profit?
Allowable deductions include salaries, rent, professional fees, travel, marketing, and many operational costs. We review your expenses to ensure you’re claiming everything you’re entitled to — nothing more, nothing less.
What is capital allowances and can my company claim it?
Capital allowances let you deduct the cost of qualifying plant, machinery, and equipment from your taxable profits. The Annual Investment Allowance (AIA) allows a 100% deduction up to £1 million — we identify all qualifying assets.
Does my company qualify for R&D tax credits?
If your company has worked on projects that involved overcoming technological or scientific uncertainty, you may qualify. R&D credits can significantly reduce your tax bill or generate a cash repayment — we assess your eligibility carefully.
What is a company tax return (CT600) and do I have to file one?
The CT600 is the form companies use to report their profits and calculate their corporation tax liability to HMRC. All active UK companies must file one, even if no tax is owed — we prepare and submit it for you.
Can I offset this year's losses against previous or future profits?
Yes — trading losses can be carried back to the previous year or carried forward to offset future profits. We identify the most beneficial approach to maximise the tax relief available to your company.
What is the director's loan account and can it affect my company's tax position?
A director’s loan account tracks money you’ve taken from or put into the company beyond your salary and dividends. Overdrawn accounts can trigger a 33.75% Section 455 tax charge if not repaid within nine months — we keep a close eye on this.
What is the difference between a dividend and a salary, and which is more tax-efficient?
A salary is subject to income tax and National Insurance; dividends are taxed at lower rates but can only be paid from company profits. The optimal split depends on your personal circumstances — we calculate the most efficient structure for you.
HMRC has opened an enquiry into my company's tax return — what should I do?
Don’t respond directly without professional advice. We manage HMRC correspondence on your behalf, gather the necessary evidence, and represent your interests throughout the enquiry process.
What records does my company need to keep for corporation tax purposes?
HMRC requires you to keep business records for at least six years. This includes invoices, bank statements, contracts, and payroll records. We advise on what to keep and in what format.
Can my company claim tax relief on charitable donations?
Yes — qualifying charitable donations made through Gift Aid are deductible from your company’s taxable profits. We ensure donations are structured correctly to maximise the relief available.
What is Business Asset Disposal Relief and when can my company use it?
Business Asset Disposal Relief (formerly Entrepreneurs’ Relief) reduces the CGT rate to 10% on qualifying business disposals. Whether it applies depends on your ownership period and involvement — we assess eligibility when you’re planning a sale.
Are there any tax planning opportunities I should consider before my year end?
Yes — there’s often more flexibility before the year end than after. We review your position a few months in advance and advise on accelerating deductions, timing of asset purchases, or pension contributions to legally reduce your liability.
My company operates in multiple countries — how is the tax handled?
International operations introduce transfer pricing rules, double tax treaties, and permanent establishment risks. We advise on cross-border structures and work with specialist advisers where needed to ensure full compliance.
