Filing a limited company tax return can feel overwhelming. Especially when you’re already juggling the day-to-day of running your business. From knowing what to report to staying on top of HMRC deadlines, there’s a lot to get right.

The good news is you don’t have to figure it out alone. At RIFT, we specialise in making company tax returns simpler, faster and more cost-effective. This is how you’ll stay compliant and keep more of what you earn.

What's included in your limited company tax return?

When you file your limited company tax return, HMRC expects two main things: your annual accounts and a Corporation Tax return, known as a CT600 form.

Your return needs to give a clear picture of your company’s financial position for the year. That means showing:

  • Total turnover
  • Allowable business expenses
  • Director salaries
  • Any dividends paid to shareholders

Profit is worked out by subtracting your allowable costs from your turnover. You’ll then pay Corporation Tax on those profits.

Allowable expenses can include things like business travel, IT equipment, insurance and training costs, but it’s important to be accurate. HMRC needs to see that your figures add up and that you’re not claiming for anything that doesn’t qualify.

Your CT600 form is where you report your profit, calculate your tax bill and declare other key information. It’s a vital part of staying compliant and it needs to be spot on.

How much corporation tax do you pay?

For the 2025/26 tax year, the Corporation Tax rate your limited company pays depends on how much profit you make:

  • Profits under £50,000: 19% Corporation Tax
  • Profits over £250,000: 25% Corporation Tax
  • Profits between £50,000 and £250,000: Marginal Relief may apply

Marginal Relief helps small and growing businesses pay less tax as they scale. For example, if your company makes £100,000 in profit, you won’t pay the full 25%. Instead Marginal Relief reduces your bill proportionally between the lower and upper thresholds.

This is where things can get confusing. Remember:

  • You pay tax on profit, not revenue
  • Dividends come out after tax, not before
  • Marginal Relief isn’t applied automatically, you need to calculate it or get help

Understanding the rules around corporation tax for small businesses can save you money and stress. If you’re wondering how much corporation tax you need to pay, getting expert advice can make all the difference.

HMRC deadlines and financial years

Unlike Self Assessment, limited company tax return deadlines vary depending on your company’s financial year. This is how it works.

  • Your Corporation Tax return is due 12 months after the end of your accounting period
  • Your Corporation Tax payment is due nine months and one day after the end of that period

For example, if your financial year ends on 31 March, your tax return is due by the following 31 March and your tax payment is due by 1 January.

Miss a deadline and HMRC will issue a penalty, starting at £100 and increasing the longer you leave it. If you’re more than three months late, HMRC might also estimate your tax bill and charge interest.

So when is your limited company tax return due? The answer depends entirely on your company’s year-end. Just don’t leave it to chance.

What you need to submit with your company tax return

Filing your limited company tax return means sending two key documents to HMRC.

1. Statutory annual accounts

This must include:

  • Balance sheet — showing everything the company owns and owes at year-end
  • Profit and loss account — detailing your income, costs and overall profit or loss
  • Notes to the accounts — explaining any important figures
  • Director’s report — a summary of the company’s performance

2. Corporation Tax return

Also known as a CT600 form, this shows your company’s taxable profit and how much Corporation Tax you owe. It also includes adjustments from your accounts and applies any tax reliefs or allowances.

Getting this right matters. Your accounts need to meet UK accounting standards and any errors could trigger penalties or HMRC investigations.

What are the pros and cons of a limited company?

A lot of self-employed people choose to set up Limited Companies.

Pros

  • They limit the amount of money you stand to lose if it all goes wrong.
  • They can lower your personal tax bill.
  • There's also a certain prestige that goes along with setting up this way. It's a sign that you're taking your business seriously, which can help when you need to impress lenders or customers.

Cons

  • You're giving up some privacy.
  • There are set-up costs.
  • You're also bulking up your bookkeeping workload. For example, since your company's money isn't strictly yours, you have to make separate tax returns for it from your own.

Tips to reduce your corporation tax bill

There are several smart, legal ways to lower your Corporation Tax bill, and many small businesses miss out by not using them fully. Four ways to make your money go further include:

  1. Maximise allowable business expenses. Claim travel, IT equipment, insurance and training. If it’s wholly and exclusively for business, these are likely deductible.
  2. Use your director’s salary and dividends wisely. A balanced mix helps reduce both Corporation Tax and personal tax. Just remember that dividends can only be taken from post-tax profits.
  3. Claim your annual event allowance. You can spend up to £150 including VAT per person on a staff party each year and it’s tax-deductible.
  4. Time your purchases. Making business-related purchases before your financial year ends can reduce that year’s taxable profit.

Looking to reduce Corporation Tax further? Our experienced tax advisers can help spot extra opportunities you might not even know about.

What records do you need to keep?

There's a lot of paperwork involved in being a company director, or even just an employee. You should obviously keep all your P45, P60 and P11D documents, but that's not all. Taxed award schemes, redundancy payments and a whole range of benefits all come with records to hold onto. You should also remember to keep track of any essential expenses you've had. You might be able to use them to bring down the tax you owe.

HMRC will expect you to tell them about any benefits you've received, whether that's Jobseeker's Allowance, Sick Pay or Statutory Maternity Pay. You should also record any income or other benefits you've had from things like employee share schemes. It's all part of the big-picture overview of your finances that the taxman wants to see.

Should you hire an accountant for your limited company?

If you’re trying to save money, it’s tempting to handle your HMRC company tax return yourself. But managing your own accounts takes time, attention to detail and a solid understanding of tax rules. For many directors, it ends up being more hassle than it’s worth.

Hiring a professional accountant can save you time and money. A good accountant will:

  • Make sure your return is accurate and compliant
  • Identify expenses and reliefs you might miss
  • Help you plan smarter for the year ahead

Our tax experts work with limited company directors every day. We know the system inside out and we’ll guide you through every step. With us on your side, you can focus on running your business while we take care of the paperwork.

Get your limited company tax return right

Sorting out your limited company tax return doesn’t have to be a headache. Getting it right means staying on the right side of HMRC, avoiding penalties and making sure you’re not paying more tax than you should.

We’ve helped thousands of small businesses get their tax returns filed accurately, on time and with confidence. Let us take the pressure off and help you make the most of what you’ve earned.

Get in touch with our team today to see how we can help.

Limited company tax return FAQs

When is my limited company tax return due?

Your return is due 12 months after your financial year ends. But your Corporation Tax payment is due nine months and one day after year-end.

What’s included in a limited company tax return?

You’ll need to submit your annual accounts and a CT600 form. These show your turnover, expenses, profit, salaries and dividends.

How do I reduce my corporation tax bill?

Claim all allowable expenses, balance salary and dividends, and use the £150 per person annual event allowance. Timing purchases helps too.

Do I need an accountant for my limited company?

While not a legal requirement, an accountant can save time, spot savings and keep you compliant. Most directors find it’s worth the cost.

What happens if I miss my corporation tax deadline?

You’ll get a £100 fine to start off. HMRC might also estimate your tax and charge interest.

How do I file a CT600 form?

Online via HMRC’s Corporation Tax portal. You’ll need your annual accounts and profit figures. Here’s a quick guide.

Can I do my own corporation tax return?

While you can do your own return, it’s easy to miss things. Many directors prefer expert help to get it right and avoid penalties.