iXBRL Tagging Service

iXBRL accounts explained.

It’s mandatory for most UK businesses to file financial statements and computations at HMRC in iXBRL format. This overview will explain iXBRL tagging in more detail, and the steps your business needs to take to ensure your company returns are compliant.

If you’d like some support in managing the complexities of iXBRL tagging when it comes to your tax and accounting returns, contact our HWB team today.

What is iXBRL?

XBRL stands for inline eXtensible Business Reporting Language. Its purpose is to allow you to accurately tag financial data in a format that both a computer and a human can read and it’s a method of recording that’s being increasingly adopted in financial institutions worldwide.

iXBRL (inline XBRL) is a more recent version of the language that allows financial data to be presented in a format that is readable by machines as well as by humans.

Each piece of financial data is assigned a computer readable iXBRL tag. iXBRL tagging works in the background to communicate information to a computer programme scanning the document, while the document itself is still written in a format that a human can read.

In this capacity, iXBRL is an evolution of XBRL, a type of eXtensible Business Reporting Language which presented information solely as tags and numbers. The human-centred iXBRL approach now ensures that everyone, and not just a machine, can read the data contained in the document.

Why iXBRL?

With a handful of exceptions, it has been compulsory for most companies to submit financial statements and computations in their online tax returns to HMRC in iXBRL format since January 2010 and non-compliance is punishable by a financial penalty.

One of the biggest benefits of filing computations using iXBRL tagging is that it is easily quantifiable and trackable. This allows institutions like HMRC to identify where trends are emerging, as well as to uncover any issues at an early stage. Furthermore, it expedites the process, minimises mistakes, and saves on resource, while helping businesses to ensure they’re adhering to all the compliance rules.

Another key benefit of iXBRL accounts is the ability to quickly recognise accounting inconsistencies. This makes it easier to uncover instances of corporate fraud or financial misconduct, making it more difficult for individuals to embezzle or syphon money illegally.

Who needs to file in iXBRL?

You will need to file in iXBRL format if you prepare accounts in accordance with the below legislation:

  • Chapter 4 or Part 15 of the Companies Act 2006
  • Building Societies Act 1986
  • Friendly and Industrial and Provident Societies Act 1968
  • Friendly Societies Act 1992
  • Insurance Accounts Directive Regulations 2008

You will also need to submit iXBRL accounts if:

  • You’re an overseas company resident in the UK
  • Your company is based overseas but you trade in the UK through a permanent UK base

iXBRL Tagging

What needs to be filed in iXBRL?

iXBRL accounts must contain the following documents:


  • A company balance sheet, calculated to the last day of the relevant financial year, that displays the name and signature of the company director
  • Your profit and loss accounts for the financial year
  • Any relevant notes pertaining to the accounts you’re submitting
  • A report from the company directors (not relevant for micro-entities)
  • An auditor’s report (if relevant for the size of your company)

In order to be iXBRL compliant, all financial data displayed within these documents needs to be assigned an iXBRL tag. The applies each time the data set appears, and not only in the first instance.

iXBRL tagging must comply with UK accounting standards. At time of publishing, the taxonomies for filing with HMRC and Companies House include:

  • FRC Accounts Taxonomy
  • EU-adopted International Financial Reporting Standards (IFRS)
  • Financial Reporting Standards (FRS) 101
  • FRS 102 Section 1A Small Entities
  • FRS 105 (The Financial Reporting Standard applicable to Micro-entities)
  • Computational Taxonomy (CT)
  • Detailed Profit and Loss Taxonomy.

When do you file iXBRL accounts?

XBRL files need to be submitted at the same time as your CT600. You must file your return within 12 months of the end of the accounting period the return covers.

How HWB can help with iXBRL accounting

There’s no doubt about it: iXBRL is a complex and highly technical process. Accidental non-compliance is enough to land your business in hot water.
With so many pieces of legislation guiding iXBRL practice, and innocent mistakes easy to make, it pays to enlist an expert in iXBRL who can ensure you file correctly and before the deadline. This means submitting your iXBRL accounts at the same time as your CT600 and within the allotted timeframe.


If you’d like some support in managing the complexities of iXBRL tagging when it comes to your tax and accounting returns, contact our HWB team today on

023 8046 1200 or email admin@hwb-accounts.com.

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