What is a Corporation Tax Return and When is it Due in the UK?


A Corporation Tax Return in the UK is a formal declaration made by limited companies and other corporate entities to report their taxable profits to HM Revenue and Customs (HMRC). This return serves as a means for companies to calculate the amount of Corporation Tax they owe based on their profits for a specific accounting period. 

Corporations in the UK are required to implement this tax, which is administered by HMRC. It applies to all types of businesses that are incorporated under UK law, including private companies limited by shares, public limited companies, and foreign companies with a UK branch or office that generates taxable profits. 

This tax ensures that corporations contribute their fair share towards public funds, supporting essential services and infrastructure across the country.

What is Corporation Tax?

Corporation Tax is a tax imposed on the profits of UK-based limited companies and other corporate entities. When filing a Corporation Tax return, companies are required to calculate their taxable profits, which may differ from the profits shown in their annual financial statements. 

This tax calculation involves deducting allowable expenses and any reliefs or allowances from the total income generated during the accounting period. Companies then determine their Corporation Tax bill based on the applicable tax rate, which can vary depending on the level of profits earned. 

Businesses have the option to prepare and file their Corporation Tax returns independently or enlist the services of an accountant for professional assistance. 

Moreover, for those with a limited company structure, it is often possible to submit annual accounts to Companies House concurrently with the Corporation Tax return, streamlining the administrative process.

Why Do You Need to Register for Corporation Tax?

Registering for Corporation Tax in the UK is a legal requirement for all limited companies, as well as foreign companies with a UK branch or office that generates taxable profits. It is essential because Corporation Tax ensures that companies contribute to the funding of public services and infrastructure through their taxable profits. 

By registering, companies comply with HMRC regulations and gain access to various reliefs, allowances, and deductions that can reduce their tax liability. Additionally, filing Corporation Tax returns accurately and on time is crucial to avoid penalties and interest charges imposed by HMRC. 

Registering promptly upon starting a business or becoming liable for Corporation Tax ensures that companies operate within the bounds of the law and fulfill their financial obligations to the UK government.

Who Pays Corporation Tax?

Corporation Tax in the UK is paid by a variety of entities beyond just traditional limited companies. Here’s a breakdown of who pays Corporation Tax:

Who Pays Corporation Tax

Limited Companies: This includes private companies limited by shares (Ltd), public limited companies (PLC), and guarantee companies.

Foreign Companies: Non-UK resident companies with a UK branch or office that generates taxable profits.

Members’ Clubs, Societies, and Associations: These entities are liable for Corporation Tax on their taxable profits.

Trade Associations: Organisations formed to represent and promote the interests of a particular industry or trade.

Housing Associations: Non-profit organisations that provide affordable housing and related services.

Co-operatives: Groups of individuals or businesses working together for mutual benefit, such as worker co-operatives or agricultural co-operatives.

When Do You Pay Corporation Tax in UK?

The deadline for Corporation Tax payments in the UK is determined by your company’s accounting period, which typically spans 12 months. For instance, if your limited company began operations on 20th January 2023, and your first accounting period concluded on 31st January 2024, you’ll need to file two separate Company Tax Returns. 

The first return covers the period from 20th January 2023 to 19th January 2024, and the second from 20th January 2024 to 31st January 2024. The filing deadline for these returns is 12 months after each respective accounting period ends. 

Therefore, the due date for your first Company Tax Return, covering the initial period, would be on or before 31st January 2025. Subsequent returns will follow annually thereafter, aligning with your company’s specific accounting period. 

It’s essential to meet these deadlines to avoid penalties and ensure compliance with HMRC regulations regarding Corporation Tax.

Rates of Corporation Tax

Corporation Tax rates in the UK vary depending on the level of taxable profits reported by limited companies. Here’s a breakdown of the current rates:

Companies reporting profits of…

Pay Corporation Tax at a rate of…

Small profit rate: Less than £50,000


Main profit rate: More than £250,000


These rates determine the percentage of profits that companies are required to pay as Corporation Tax to HMRC. Small companies with profits below £50,000 benefit from a lower rate of 19%, while larger companies with profits exceeding £250,000 are subject to a higher rate of 25%. It’s important for businesses to accurately calculate their profits and apply the appropriate rate to ensure compliance with tax regulations and optimise their financial planning.

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How to File/Submit a Corporation Tax Return?

Filing a Corporation Tax Return in the UK involves several steps to ensure compliance with HMRC regulations. Here’s a detailed guide:

How to File/Submit a Corporation Tax Return?

Prepare Financial Statements: Compile accurate financial statements, including profit and loss accounts, balance sheets, and any other relevant documents detailing income, expenses, assets, and liabilities.

Calculate Taxable Profits: Deduct allowable expenses, reliefs, and allowances from total income to arrive at taxable profits.

Register with HMRC: Ensure your company is registered for Corporation Tax with HMRC and obtain your Unique Taxpayer Reference (UTR) if you haven’t already.

Complete the CT600 Form: Use HMRC’s CT600 form to report your taxable profits, ensuring all details are accurately filled in.

Submit Supporting Documents: Attach financial statements and any necessary computations that support the figures entered on the CT600 form.

File Online or by Post: Submit your Corporation Tax Return online through HMRC’s online services or by post, adhering to the deadlines specified by HMRC.

Pay Corporation Tax: After submitting your return, pay any Corporation Tax owed to HMRC by the deadline to avoid penalties and interest charges.

How to Submit CT600 and Company Tax Returns?

Submitting your CT600 form and Company Tax Return in the UK involves several straightforward steps. You can complete the CT600 form online, providing details of your company’s taxable profits along with your financial accounts and any supporting documentation. 

This form is essential for reporting your corporation tax liability to HMRC. While you have the option to engage an accountant to handle this process on your behalf, ensuring accuracy and compliance remains your responsibility. 

It’s crucial to submit the CT600 form and associated documents promptly to meet HMRC’s deadlines and to ensure timely payment of any Corporation Tax due. 

This proactive approach helps avoid penalties and maintains good standing with HMRC, facilitating smooth operations for your business.

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Closing Note

Understanding what a Corporation Tax Return entails and its due date in the UK is essential for every company operating within its borders. It’s a legal requirement for corporations to accurately report their taxable profits to HMRC through the CT600 form, ensuring compliance with tax laws and timely submission to avoid penalties. By staying informed about these obligations, businesses can manage their finances effectively and contribute responsibly to the country’s economic framework.


Ans: The deadline for paying Corporation Tax depends on your company's accounting period. Typically, Corporation Tax is due nine months and one day after the end of your accounting period. For example, if your accounting period ends on 31st December, Corporation Tax would be due on or before 1st October of the following year.
Ans: The deadline for filing a Corporation Tax Return (CT600) is 12 months after the end of your accounting period. This means you must submit your completed CT600 form to HMRC within this timeframe to avoid penalties.
Ans: Allowable expenses are costs incurred wholly and exclusively for the purpose of your business. This can include expenses such as employee wages, rent for business premises, office supplies, and business travel. It's important to keep accurate records of these expenses to claim them against your taxable profits.
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