Business Tax Accountants in London
Corporation Tax is no longer a single flat rate, and it runs on two deadlines that don't align — one set by HMRC, one set by Companies House. Miss either and the penalties escalate automatically, regardless of how genuine the oversight was.
Business tax rarely stays simple for long. Corporation Tax is no longer a single flat rate, filing runs on two separate clocks — one set by HMRC and one set by Companies House — and missing either brings automatic, escalating penalties regardless of how genuine the oversight was. For a growing business, keeping pace with all of it in-house, on top of actually running the business, is rarely realistic.
The Finance Equation Ltd is an award-winning, ACCA-regulated firm of chartered certified accountants with over 30 years' experience, providing business tax accountancy services to companies across London — making sure every Corporation Tax obligation is met accurately and on time, while you keep as much of what the business earns as the law allows. It's one part of our wider taxation services, alongside property tax, personal tax, tax planning and tax investigations support.
Two filing clocks, one set of books — we track both so nothing slips through the gap.
Built For Businesses at Every Stage
We begin with a thorough assessment of your company's circumstances — its structure, its transactions and its plans — to determine your obligations correctly from the outset and structure the business for growth, not just this year's return.
Filing for the first time
First-year businesses filing a Company Tax Return for the first time, getting the structure and the rate calculation right before habits are set.
Multi-director complexity
Established, multi-director businesses whose corporation tax position has grown more complex alongside the business itself.
Structure-dependent tax
Property investment and development companies, whose tax position depends heavily on how the company itself is structured — see our property tax service for the investor side of this.
Corporation Tax: Rates, Deadlines and Getting It Right
Corporation Tax hasn't been a single flat rate since April 2023 — and the return that calculates it isn't due on the same day as the bill itself.
Profits up to £50,000.
Profits between £50,000 and £250,000, taxed on a sliding scale — see HMRC's Marginal Relief calculator.
Profits over £250,000.
Get the calculation wrong, or miss which rate actually applies to your company, and you either overpay unnecessarily or under-declare and face a correction later. Full detail behind each band is in HMRC's Corporation Tax rates guidance.
after the same period ends — a full three months earlier than the return itself. See HMRC's guidance on paying your Corporation Tax bill.
The deadlines don't align, which is exactly where companies get caught out. We work to the payment deadline, not the filing deadline, so you're never caught paying late simply because the return wasn't due yet.
Filing Late Is Expensive — On Two Fronts
Miss either deadline and the penalties escalate automatically — and it's entirely possible to owe both at once, because HMRC and Companies House track them separately.
Escalating from day one
- £200the day after the deadline
- £200at 3 months
- +10% of unpaid taxat 6 months
- +10% of unpaid taxat 12 months
- £1,000 flatafter 3 late filings in a row
Percentage penalties are calculated against HMRC's own estimate of what you owe. See HMRC's penalties for late filing.
A separate clock entirely
- £150up to 1 month late
- £3751–3 months late
- £7503–6 months late
- £1,500more than 6 months late
Penalties double if accounts are filed late two years running. See Companies House's late filing penalties.
We track them as two distinct obligations, not one — so a single missed date never quietly becomes two separate bills.
Reliefs That Are Too Often Left on the Table
Corporation Tax isn't only about what you owe — it's also about what you're entitled to claim back. Many eligible businesses never claim R&D tax relief, either because they don't realise their work qualifies or because identifying and evidencing the claim properly takes specialist time they don't have. We assess whether your projects qualify and prepare the claim alongside your Company Tax Return, so a genuine relief isn't left unclaimed.
What actually qualifies
Support for companies chargeable to UK Corporation Tax working on projects seeking a genuine advance in science or technology by resolving a real scientific or technological uncertainty.
Not routine improvement — work a competent professional in the field would recognise as new.
Company Accounting — What We Do For You
We're passionate about helping clients keep more of what they earn, and that starts with handling the full compliance picture in one place — so nothing falls through the gap between three different suppliers who don't talk to each other.
HMRC registration, checked and confirmed
So your company is registered correctly from the outset, not discovered to be wrong at the worst possible moment.
Company Tax Return preparation and filing
Calculated accurately against the current rate structure and filed within the payment deadline, not just the filing one.
Liability determination and payment management
So you know what's owed, when — and it's paid on time, every time.
Ongoing legislative monitoring
So rate changes and new reliefs are factored into your planning as they happen, not discovered a year later.
Advance tax planning
Structuring the business for growth and risk mitigation, rather than reacting to a bill once it lands.
Cloud accounting on Xero and QuickBooks
Keeping your records accurate and current on our cloud accounting platforms — and saving you time better spent running the business.
Legislative changes and new reliefs, factored into your numbers as they happen — not discovered a year later.
VAT and Making Tax Digital
Most growing companies eventually cross into VAT territory, and the rules apply the moment they do. If your taxable turnover goes over £90,000 in any rolling 12-month period, you must register for VAT within 30 days of the end of the month you crossed the threshold. Once registered, almost all VAT-registered businesses must follow Making Tax Digital rules, filing electronically through compatible software rather than on paper — one more compliance clock running alongside your Corporation Tax obligations, not instead of them.
Why Businesses Choose Finance Equation
We're an award-winning, ACCA-regulated practice with more than 30 years advising companies on corporation tax, compliance and structuring — not a service bolted onto general bookkeeping. Every recommendation is built around your company's actual circumstances, not a generic template, and every platform we use has been tested and vetted by our own team first.
Because we're chartered certified accountants first, the technology and the filings sit behind advice from people who understand your business and your numbers — so when HMRC or Companies House raise a query, you're never left explaining yourself alone. As your company grows, that same team can step in as your Fractional AI CFO, turning clean compliance into forward-looking planning.