GfC17 refers to HMRC’s new Guidelines for Compliance titled “Help with sharing group structure information”.
These guidelines were released in February 2026. They provide a best-practice framework for large and complex businesses to share clear, consistent information about their group structures and transactions with HMRC.
While not mandatory, following GfC17 can save time and reduce misunderstandings. It also helps to build a more collaborative relationship with HMRC.
In this guide, you’ll get to know:
- Why HMRC introduced GfC17 guidance for large businesses
- When large businesses need to share group structure information with HMRC
- What key details does HMRC want to see
- And much more…
Let’s get into it!
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What Is GfC17? Why Did HMRC Introduce GfC17 Guidance for Large Businesses?
You might be wondering why HMRC felt the need to release a whole new set of guidelines just for group structure charts. The truth is, for a long time, large businesses were sending in all sorts of different diagrams. Some were hand-drawn, some were missing key details, and others were just plain confusing. GfC17 was created to fix that.
It stands for “Guidelines for Compliance 17,” and it is basically a “best practice” manual for sharing group structure information. By following it, you are essentially speaking HMRC’s language.
This makes their job easier, which in turn makes your life easier because it leads to fewer “please explain this” emails and a much faster risk review process (BRR+).
For a large business, the benefit of sharing group structure information using these standards is simple: it builds trust. When you provide a clear map of your business, HMRC is less likely to think you are hiding something in a complex web of offshore entities or hybrid structures.
When Large Businesses Need to Share Group Structure Information With HMRC?
You don’t need to send this information every single day, but there are specific moments when HMRC will expect to see a clear “family tree” of your business:
- During your Business Risk Review (BRR+), HMRC decides if your company is “low risk” or “high risk.”
- If you buy a new company, sell a branch, or move parts of the business overseas.
- When you apply for Statutory Clearance (asking HMRC to “OK” a tax move before you do it).
- If HMRC is double-checking your tax returns and needs to see exactly who owns what.
What Key Details Does HMRC Want to See?
When sharing group structure information, HMRC expects at least five key details for every entity:
- Entity Name: The full legal name of the entity.
- Entity Type: Whether it is a company, partnership, branch, or trust.
- Ownership & Control: Clear details on ownership percentages and how control is exercised.
- Tax Jurisdiction: The country of tax residence and the country of incorporation (if they are different).
- Special Characteristics: Identification of hybrids, charities, joint ventures, or specific partnership types.
How Should You Format Your Group Structure Charts?
HMRC also recommends using consistent, standard notation for diagrams, which includes:
- Rectangles: For companies.
- Ovals: For branches or permanent establishments (PE).
- Triangles: For partnerships.
- Triangles inside rectangles: For partnership hybrids.
- Ovals inside rectangles: For company hybrids.
- Diamonds: For trusts.
- Circles: For individuals.
- Solid lines: To represent ownership.
When sharing group structure information, using these symbols helps avoid the back-and-forth emails where an inspector asks, “Is this a subsidiary or just a branch?”
Important: If you have a “hybrid” entity (something that’s a company in one country but a partnership in another), HMRC suggests putting one shape inside another, like a triangle inside a rectangle.
What Are the Steps to Follow GfC17 Correctly?
If you want to get this right and stay on HMRC’s good side, here is a simple process to follow:
- Step 1: Audit your current charts. Look at the diagrams you already have. Do they include tax residency and entity types?
- Step 2: Add the “Special” details. Identify any hybrid entities or branches. HMRC specifically wants to see the “Parent” company of a branch clearly marked.
- Step 3: Use the standard symbols. Update your visual software (like Visio or Lucidchart) to match the GfC17 shapes.
- Step 4: Write a brief narrative. Sometimes a chart is not enough. A one-page summary explaining why the structure exists can prevent a lot of confusion.
- Step 5: Review annually. Group structures change. Make sharing group structure information a part of your year-end routine so your data remains accurate and up to date.
How Should You Present Complex Group Structures to HMRC?
The more complex your group, the more you need to think about the layout and layering when sharing group structure information.
HMRC suggests:
- Using standard shapes and symbols for different entity types and relationships.
- Breaking very large structures into manageable sections or partial structures.
- Supporting diagrams with a table that captures all key attributes.
- Adding short narrative notes to explain unusual features or historic quirks.
Using HMRC’s suggested symbols is optional, but it can make it easier for HMRC teams to read your charts consistently.
What Are “Partial Group Structures” and When Should You Use Them?
You do not always need to send the entire global structure chart. HMRC recognises that sometimes you only need to share part of the group when sharing group structure information with them.
Sharing partial group structure information makes sense where:
- A transaction only affects a specific subgroup.
- A particular business line or region is under review.
- Including the full group would add more noise than clarity.
GfC17 encourages this approach for complex groups, but flags that HMRC may need further checks if the partial picture raises further questions.
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Do You Need to Show Tax Residence as Well as Place of Incorporation?
Yes, where they differ.
HMRC states that if the country of legal formation is different from the country of tax residence, then both country codes should be included. You should list the country of tax residence first and the country of legal formation second.
That is a detail many generic charts skip. When sharing group structure information, HMRC expects this distinction to be clearly reflected. For HMRC, it is not a footnote. It impacts how the entity will be interpreted for UK tax purposes.
What Does GfC17 Say About Hybrid Entities?
GfC17 has a great deal to say about hybrid entities. HMRC says it needs to be able to identify hybrid entities in a group structure so it can understand complexities in the tax treatment of the entity and its transactions.
The guidance gives two examples: The first is a UK company treated as a transparent entity for US tax purposes under check-the-box regulations. The second is a partnership treated as a corporation in another country.
HMRC advises depicting these visually. You should use an oval inside a rectangle for a company hybrid and a triangle inside a rectangle for a partnership hybrid.
A major gap in most existing group charts is that they show the legal form but fail to show the tax character mismatch across jurisdictions. HMRC needs to see how each entity is characterised for tax purposes. This detail matters significantly when you are sharing group structure information.
Is Your Chart Missing These “Hidden” Details?
HMRC is often looking for things that aren’t strictly “ownership.” When sharing group structure information, check if you should also be showing:
- Permanent Establishments (P.E.s): If you have a branch in another country which has no separate legal entity, then you will need to show this on the diagram using an oval.
- Trusts: Trusts form part of the ownership chain and should be shown as a diamond. These entities are a key focus area for HMRC auditors.
- Joint Ventures: If you do not have a majority shareholding but you have a material interest, it will need to be shown on the diagram.
Is This Really Just a Documentation Issue?
Not really. It isn’t simply a document issue. On the surface, GfC17 appears to be a presentation guide, but it is actually about governance and the quality of your tax story.
In sharing group structure information, when your group structure can’t be explained in clear terms, that normally identifies one of three issues:
Documentation issue.
Governance issue.
Or an actual underlying complexity issue, which will need some form of active management.
All three can also appear at the same time, creating additional compliance complexity.
What Are the Common Mistakes HMRC Sees in Group Structure Information?
HMRC frequently identifies errors in how businesses document and report their group structures. Some of these errors may result in denied tax relief, fines, and longer-than-expected investigations.
Some critical mistakes when sharing group structure information are:
- Inconsistent data: Providing a group chart that contradicts information held in the tax computation or the statutory accounts.
- Missing “Special” entities: Failing to clearly identify entities that require specific tax treatment, such as hybrids, joint ventures, or charities.
- Ambiguous residency: Errors in reporting the country of incorporation versus the actual country of tax residence, or failing to show both when they differ.
- Poor visual clarity: Using non-standard symbols or overlapping lines that make it impossible to trace the chain of ownership or control.
- Outdated information: Submitting charts that have not been updated for recent acquisitions, disposals, or internal liquidations. This can raise concerns regarding your tax governance during a BRR+ review.
- Lack of narrative: Failure to include written explanations for unusual structures or historical anomalies that the diagram cannot adequately describe.
Is Sharing Group Structure Information Mandatory Under GfC17?
Technically, no. GfC17 is a guideline, not a legally binding document, such as a tax return. But ignoring the guidelines may bring HMRC’s scrutiny down on you, especially if they have to spend hours investigating your affairs.
By contrast, following GfC17 will give you a better chance of receiving a “Low Risk” rating for your Business Risk Review+. This generally means fewer audits from HMRC and a less complicated relationship with your Customer Compliance Manager (CCM).
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The Bottom Line
HMRC’s new GfC17 guidance does not force large businesses into a new filing regime, but it does make HMRC’s expectations much clearer.
Good sharing group structure information means clearly showing entity type, ownership or control, tax jurisdiction, special characteristics and, where relevant, the flow of transaction.
Get that right, and your dealings with HMRC are likely to be faster and clearer. Get it wrong, and you may invite extra questions that could have been avoided.
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Disclaimer: All the information provided in this article on “How to Share Group Structure Information with HMRC: What GfC17 Means for Large Businesses” including all the texts and graphics, is general in nature. It does not intend to disregard any of the professional advice.