Corporation tax services
Taking care of the preparation
and filing of your company tax return
Deal with HMRC directly so you always pay the correct amount in tax.
Competitively priced, no hidden extras
Coupled with great customer support.
Transparent pricing
Qualified team of tax advisors
Tax planning & business support guidance
Advanced preparation of your accounts
Corporation tax return (CT600)
A Corporation tax return (also known as CT600 form) must be filed with HMRC by all Limited Companies within 12 months after the financial year.
The first step is to notify HMRC that your company is subject to corporation tax. If your company must pay corporation tax, you must determine how much profit it makes each accounting period and how much tax is due.
A 12-month accounting period is maximum. So even though the CT600 isn’t due for another year, it must be paid within nine months and one day of the year’s end. Late returns or payments are subject to a penalty and possible interest. If in doubt, check the Companies House website to see when your company’s fiscal year ends.
Corporation Tax, like many other taxes in the UK, is complex. A professional tax advisor can help you plan to minimise your tax liability.
Individuals, sole traders, and partnerships are not required to pay Corporation Tax but must instead file self-assessment tax returns (also known as Personal Tax Return or SA302).
Penalties for late filing of the CT600 company tax return
If you miss the deadline to file your company tax return, fines can mount up very quickly, and HMRC may charge you one of the following fines up to a year:
- One day late: £100 penalty
- Three months late: Another £100 penalty
- Six months late: An additional penalty of 10% of your estimated corporation tax bill. HMRC makes this estimate, and you are unable to appeal against it.
- Twelve months late: Another 10% penalty of your estimated corporation tax bill.
Need to do a corporation tax return for your company?
Call us today and speak to one of our qualified tax advisors.
We have made the whole process of completing your company tax return stress-free.
Fusion services
We provide a comprehensive range of accounting and tax services to help launch your new venture.
Case study – limited company tax planning & advisory
David is thriving with smarter company tax planning
David, a company director, was frustrated by paying more tax than he thought necessary and unsure how best to structure his income. “I felt like I was missing something,” he admitted. Fusion stepped in with tailored advice, balancing salary and dividends while highlighting reliefs he didn’t know he could claim. We built a proactive tax plan that not only reduced his liabilities but freed capital to reinvest into staff and systems. Quarterly check-ins kept everything on track, and David quickly realised Fusion was more than just accountants — we were growth partners. Today, he credits Fusion with giving him confidence, clarity, and thousands saved each year to fuel his expansion plans.
Fusion Accountants didn’t just file my accounts — they actively helped my company grow.
David Harris
–
Company Director
Our complete service
Planning
Tax planning is probably the most crucial step. Our qualified advisors will help you determine the most tax-efficient business structure or equity planning.
Tax reliefs & opportunities
Understanding all available tax reliefs and opportunities is critical. We will guide you through the process and ensure you receive all eligible benefits.
End to end service
We will not only calculate your CT600 and submit it to HMRC on your behalf, but also answer any questions HMRC may have.
Never miss a deadline
As you accountants, we will ensure you never miss a deadline. We don’t wait until the end of the year to start working on your accounts.
FAQ ‘s
What is Corporation Tax return?
In simple terms, corporation tax return is an account of a company’s income and expenses and the resulting tax liability.
Who needs to file Corporation Tax Return?
Every company needs to file Corporation tax return when they receive a notice to file one from the HMRC. You do not need to file a corporation tax return if you are a sole trader/self-employed or in partnership.
Do I need to register my company for tax?
You will need to register your company for corporation tax within 3 months of starting the business i.e., starting to buy and sell goods and services, employing staff, etc
What if I am late in registration for Corporation tax?
You may have to pay a penalty if you get late in registration for corporation tax. The penalty starts from £100.
Who is responsible for registering and filing for corporation tax?
A company director is responsible for registering and filing for corporation tax.
What company information is required by HMRC?
You will need to have your HMRC government gateway account to register online. You will need to provide the following information to HMRC at the time of registration.
- Company registration number
- The date the company started business
- Company accounting period
You can register for corporation tax here using your government gateway account.
How much Corporation Tax will I have to pay?
As of 1 April 2023, a small profit rate of 19% will apply if the taxable profit of your company is £50,000 or less. If the taxable profit is between £50,000 and £250,000, the main rate of 25% will apply which will be reduced by a marginal relief.
Do I need an accountant for my company?
There is no legal requirement to appoint an accountant to do your company’s tax return. However, a qualified accountant can help you complete and file your company tax return stress free and most importantly without costly errors.
Do dormant companies have to pay taxes and file tax returns?
If your company is dormant, you do not need to file a company tax return. However, you need to inform HMRC that your company is dormant i.e., not trading. Otherwise, you will need to file the company tax return.
Corporation tax support for London-based companies
We help companies across London — including Hounslow, Brentford, Kingston, East London, Harrow, and Staines — stay on top of their corporation tax responsibilities. From annual returns to tax planning, Fusion Accountants ensures you never miss a deadline. Our local support gives your business a competitive tax edge.
Accountants in Hounslow & Brentford
Our flagship Hounslow office also serves Brentford and surrounding areas, helping local businesses.
Accountants in London
Located in the heart of the capital, our London office supports entrepreneurs, creatives, and established businesses with tax, accounting, and strategic advice.
Accountants in East London
From startups to growing SMEs, our East London team works with businesses across Hackney, Stratford, and beyond to simplify compliance and boost profitability.
Accountants in Harrow
Serving sole traders and small businesses in Harrow and surrounding areas, we offer fixed-fee packages and personalised tax planning solutions.
Accountants in Kingston
Our Kingston office provides accounting and advisory support to professionals and landlords across Surrey and South West London.
Accountants in Staines
Conveniently located near Heathrow, our Staines team works with contractors, eCommerce businesses, and SMEs across West London and Surrey.