Guidance
Restriction on Corporation Tax relief for interest deductions
Check if your company’s or group’s interest deductions for Corporation Tax will be restricted, and if you need to send a Corporate Interest Restriction return.
When you calculate how much UK Corporation Tax your company or group has to pay, there’s a limit (known as a Corporate Interest Restriction) to the amount of tax relief you can get for deducting net interest and other financing costs.
This Corporate Interest Restriction only applies to individual companies or groups of companies that will deduct over £2 million in a 12-month period.
If your company’s or group’s net interest and financing costs are restricted, you should appoint a reporting company within 12 months of the end of the period of account. The reporting company must then submit a Corporate Interest Restriction return.
If you’ll deduct less than £2 million
Your company or group does not need to submit a Corporate Interest Restriction return. However, you must keep documents that show that your company or group will not deduct more than £2 million in net interest and financing costs in that period of account.
You can still appoint a reporting company, which must then submit an abbreviated return. If you do, you can carry forward unused interest allowance for up to 5 years to reduce a future interest restriction, by replacing that abbreviated return with a full return for that period of account.
If you’ll deduct more than £2 million
You must work out your company’s or group’s ‘interest allowance’. This is the maximum amount of net interest and financing costs your company or group can deduct in a period of account.
You can use the ‘fixed ratio method’ or the ‘group ratio method’. Use the method that gives you the largest allowance.
You must keep records of your calculation.
If your company’s or group’s net interest and financing costs are restricted, you should normally appoint a reporting company within 12 months of the end of the period of account, then submit a full Corporate Interest Restriction return.
Fixed ratio method
Using the fixed ratio method, the interest allowance is the lower of:
- 30% of the company’s or group’s UK taxable profits before interest, taxes, capital allowances and some other tax reliefs
- the company’s or group’s worldwide net interest expense
Group ratio method
To use this method, you must:
- appoint a reporting company
- elect to use the method in a Corporate Interest Restriction return
Using the group ratio method, the interest allowance is the lower of:
- the ratio of the company’s or group’s worldwide net interest expense owed to unrelated parties, to the company’s or group’s overall profit before tax, interest, depreciation and amortisation multiplied by the company’s or group’s taxable UK profits before interest and capital allowances
- the company’s or group’s worldwide net interest expense owed to unrelated parties
Find more detailed guidance on how to calculate your company’s or group’s interest allowance.
If your interest deductions are not restricted
You can appoint a reporting company, which must then submit an abbreviated return. If you do, you can carry forward unused interest allowance for up to 5 years to reduce a future interest restriction, by replacing that abbreviated return with a full return for that period of account.
Appoint a reporting company
Individual companies and groups can appoint a reporting company. Your reporting company will be responsible for submitting your company’s or group’s Corporate Interest Restriction return. The reporting company must be:
- liable to UK Corporation Tax
- non-dormant
- authorised by at least 50% of the group’s non-dormant companies (which are liable for UK Corporation Tax) to be appointed as the reporting company
When you have appointed a reporting company, you must submit a Corporate Interest Restriction return for every period of account, including when there’s no interest restriction. If you revoke the appointment of a reporting company and do not have an interest restriction, you will not have to submit a return.
If you do not appoint a reporting company, HMRC might appoint one for you.
Tell HMRC about the appointment of your reporting company
To appoint a reporting company:
- Fill in the template.
- Complete the online form and upload the template.
Complete the online form and upload the template. To use the online service, you need a Government Gateway user ID and password. If you do not have a user ID, you can create one when you use the service.
You only need to appoint a reporting company once.
To change your reporting company, you’ll need to tell HMRC you want to revoke your current reporting company and appoint a new one. This needs to be authorised by at least 50% of the group’s non-dormant companies (that are liable for UK Corporation Tax).
Submit a return
Your reporting company must submit a return within 12 months of the end of the reporting period the return is for.
Find out how to submit a full or abbreviated Corporate Interest Restriction return.
Elections
Elections let you choose a particular way of having your company’s or group’s tax treated, like choosing to use the group ratio method to work out your interest allowance. You should make elections in a Corporate Interest Restriction return.
If you need to make an election, but cannot do it in a return, send the details of the election to your Customer Compliance Manager.
Or, post the details of the election to:
Corporation Tax Services
HM Revenue and Customs
BX9 1AX
You should mention Corporate Interest Restriction in your election to help HMRC direct your letter to the correct team.
Changes due to coronavirus (COVID-19)
Due to measures put in place to stop the spread of coronavirus, HMRC will accept elections by email when they cannot be posted or included with a Corporate Interest Restriction return.
You should email elections to your Customer Compliance Manager.
If you do not have Customer Compliance Manager you can email elections to msbcorporateinterest.restrictionmailbox@hmrc.gov.uk.
This guidance will be updated when the measures end.
Penalties
If your company or group does not submit a Corporate Interest Restriction return when it should, it might have to pay a fixed penalty of:
- £500 if the return is up to 3 months late
- £1,000 if the return is more than 3 months late
If you submit an inaccurate Corporate Interest Restriction return, your company or group might have to pay a penalty of up to 100% of the extra tax (or lower tax relief) owed in the corrected return.
The amount of penalty you’ll have to pay will depend on the type of error and when you told HMRC about it. The penalty might be less if you tell HMRC about your error before they discover it.
Get help or more information
For help or more information, you can:
- read more information about Corporate Interest Restriction in HMRC’s Corporate Finance Manual
- contact your Customer Compliance Manager
- email: msbcorporateinterest.restrictionmailbox@hmrc.gov.uk - do not email returns
Published 21 December 2017
Last updated 3 April 2020 + show all updates
Last updated 3 April 2020 + show all updates
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HMRC will accept elections by email while temporary measures are in place to stop the spread of coronavirus (COVID-19).
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The timescale on when you should appoint a reporting company has been updated.
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The address to send Corporate Interest Restriction elections to has been updated.
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This guide has been updated to include more information about how to work out your company's or group's interest allowance.
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The postal address to send elections outside of the interest restriction return has changed.
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Guidance on how to submit full or abbreviated Corporate interest restriction Returns has been added.
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The Google worksheet for appointment of a reporting company has been replaced with an Excel worksheet.
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Updated with information on how to make an election outside of a return.
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This guidance has been updated to include details of how to appoint a reporting company.
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First published.