FRS 100 is the UK and Republic of Ireland accounting standard that tells your entity which financial reporting framework to use. Issued by the Financial Reporting Council, it contains no accounting rules of its own. It works as a routing mechanism, sending you to one of four destinations — FRS 101, FRS 102, FRS 105, or full UK-adopted IFRS — based on your entity’s size and structure.1Financial Reporting Council. FRS 100 Application of Financial Reporting Requirements Getting that initial classification right determines what your financial statements look like, which disclosures you must provide, and how much compliance work you face every year.
Who Has to Apply FRS 100
FRS 100 applies to virtually all entities preparing financial statements intended to give a true and fair view under UK or Republic of Ireland legislation. That covers companies, limited liability partnerships, charities, and other non-corporate entities.2ICAEW. FRS 100 Application of Financial Reporting Requirements If you file accounts under UK GAAP, FRS 100 is your starting point.
The main boundary is full IFRS. Listed companies on the London Stock Exchange must prepare consolidated accounts under UK-adopted IFRS, which sits outside FRS 100’s framework for those statements. Any UK entity can also voluntarily elect full IFRS for its statutory accounts, and that election similarly takes it out of FRS 100’s scope.
Public benefit entities — organisations whose primary objective is providing goods or services for public, community, or social benefit rather than returns for shareholders — fall within FRS 100’s scope. Charities, housing associations, and universities are typical examples. They follow FRS 102 but must also apply the specialist sections marked for public benefit entities, together with any Statement of Recommended Practice for their sector.
The Size Classifications That Drive the Routing
Your Companies Act size category determines which frameworks are available to you. The thresholds themselves come from the Companies Act 2006, not FRS 100, but FRS 100 relies on them. An entity must satisfy at least two of three criteria — turnover, balance sheet total, and average number of employees — for two consecutive financial years to qualify for a particular size.3ICAEW. UK Company Size Thresholds Have Increased
The thresholds were substantially increased for financial years beginning on or after 6 April 2025. A transitional provision lets you take advantage of the higher thresholds straight away. When determining your size for a financial year starting on or after 6 April 2025, you can treat the new thresholds as if they had applied in the previous year, rather than waiting two consecutive years under the new figures.3ICAEW. UK Company Size Thresholds Have Increased
Micro-Entities
- Turnover: not more than £1 million
- Balance sheet total: not more than £500,000
- Employees: not more than 10 on average
Micro-entities can elect to use FRS 105. Not every entity below the thresholds qualifies, though. Charities, LLPs, and certain other entity types are excluded from the micro-entity regime regardless of size.4Financial Reporting Council. FRS 105 The Financial Reporting Standard Applicable to the Micro-entities Regime
Small Entities
- Turnover: not more than £15 million
- Balance sheet total: not more than £7.5 million
- Employees: not more than 50 on average
Small entities are the main users of FRS 102’s Section 1A, which cuts the presentation and disclosure burden while still requiring full FRS 102 recognition and measurement.5Financial Reporting Council. FRS 102 The Financial Reporting Standard Applicable in the UK and Republic of Ireland Small companies generally also qualify for audit exemption, though that can be lost if the entity is a subsidiary, a public company, or has had its shares traded on a regulated market.6GOV.UK. Audit Exemption for Private Limited Companies
Medium-Sized Entities
- Turnover: not more than £54 million
- Balance sheet total: not more than £27 million
- Employees: not more than 250 on average
Medium-sized entities apply full FRS 102 without the Section 1A simplifications. They face more extensive disclosure requirements and are subject to statutory audit.3ICAEW. UK Company Size Thresholds Have Increased
Large Entities
Any entity above the medium-sized thresholds is large. Large entities apply full FRS 102 with the fullest disclosure obligations, or they may elect full IFRS. No simplified option exists for a large entity unless it qualifies as a qualifying entity within a group.
The Four Frameworks FRS 100 Points You To
FRS 105: The Micro-Entities Regime
FRS 105 is the most streamlined option, available only to entities that qualify as micro-entities. The accounts consist of a balance sheet and profit and loss account with only limited disclosures. No cash flow statement, no notes beyond the minimum, and no directors’ report is required.7ICAEW. FRS 105 The Financial Reporting Standard Applicable to the Micro-entities Regime Accounting choices available in FRS 102 are stripped out, so no deferred tax or equity-settled share-based payment amounts are recognised. The trade-off for the simplicity is that your statements contain very little detail, which can be a drawback if you need to show lenders or investors a fuller picture.
FRS 102: The Default Standard
FRS 102 is the workhorse of UK GAAP. It applies to small, medium-sized, and large entities that do not adopt full IFRS. The standard is based on the IASB’s IFRS for SMEs but has been significantly adapted to comply with UK Companies Act requirements.5Financial Reporting Council. FRS 102 The Financial Reporting Standard Applicable in the UK and Republic of Ireland
Small entities using FRS 102 get Section 1A, which reduces presentation and disclosure requirements while keeping the same recognition and measurement principles. A small entity can always choose to provide fuller disclosures. Section 1A is a floor, not a ceiling. Medium-sized and large entities apply FRS 102 in full.
FRS 101: The Reduced Disclosure Framework
FRS 101 fills a specific niche. It is available to qualifying entities within a group. A qualifying entity is one included in publicly available consolidated accounts prepared by its parent that give a true and fair view.8ICAEW. FRS 101 Reduced Disclosure Framework Both subsidiaries and parent companies can qualify.
Entities under FRS 101 adopt the recognition and measurement principles of full IFRS but with significant disclosure exemptions, because the detailed information already appears in the parent’s consolidated accounts.9Financial Reporting Council. FRS 101 Reduced Disclosure Framework That makes FRS 101 popular with subsidiaries of IFRS-reporting groups, keeping the individual entity’s accounting policies aligned with the group while cutting redundant disclosures.
One procedural requirement catches some entities out. Shareholders must be notified in writing before the entity switches to the reduced disclosure framework, and shareholders holding 5% or more of allotted shares in aggregate can object and block the election. If your register includes outside minority holders, factor in the notification step well before your reporting date.
Full IFRS
Any UK entity, whatever its size, can voluntarily prepare statutory accounts under full UK-adopted IFRS. The choice is most common among large multinational groups and entities seeking international capital, where investors expect IFRS-compliant reporting. Electing full IFRS takes those accounts outside FRS 100’s framework entirely.
What to Do When FRS 102 Doesn’t Address a Transaction
FRS 100 also sets out a hierarchy for situations where FRS 102 does not explicitly address a particular transaction or event. The standard prescribes a four-step sequence:1Financial Reporting Council. FRS 100 Application of Financial Reporting Requirements
- Look at the requirements and principles within FRS 102 itself, including any section that deals with the issue directly.
- Consider requirements and principles in other FRSs that address similar or related issues.
- Look to the requirements of UK-adopted IFRS.
- Consider generally accepted accounting principles established by custom, practice, or professional consensus, provided they are consistent with the FRC’s overall framework.
Most entities will never need to go past step one. The hierarchy matters most for unusual or complex transactions, such as a business combination with an unusual structure or a financial instrument that doesn’t fit neatly into FRS 102’s categories. When you reach into IFRS for guidance, you are borrowing the principle to fill a gap, not adopting IFRS wholesale for the transaction.
Changes Taking Effect in 2026
For accounting periods beginning on or after 1 January 2026, a substantially revised FRS 102 comes into force.5Financial Reporting Council. FRS 102 The Financial Reporting Standard Applicable in the UK and Republic of Ireland FRS 100’s role as the routing standard does not change, but the destination it sends most entities to looks quite different.
Lease accounting is the biggest shift. The old split between operating leases (expensed through profit and loss) and finance leases (on the balance sheet) is replaced by a single model aligned with IFRS 16. All leases go on the balance sheet as a right-of-use asset and a corresponding lease liability, with exemptions only for short-term leases and low-value assets. Profit and loss statements will show depreciation and interest instead of rent expense, which changes key financial ratios like EBITDA for many entities.
Revenue recognition also changes. A new five-step model aligned with IFRS 15 replaces the previous approach. You identify the contract, identify performance obligations, determine the transaction price, allocate it across obligations, and recognise revenue as each obligation is satisfied. For straightforward sales the practical impact is modest. For bundled contracts, long-term projects, or variable pricing, the transition requires real work.
Other changes include new guidance on uncertain tax positions, enhanced related party disclosures that now cover commitments as well as transactions, and a new fair value measurement section drawing on IFRS 13 principles.
Penalties for Filing Under the Wrong Framework
Filing accounts under a framework you don’t qualify for is not just a technical error. Companies House can impose financial penalties where it is satisfied beyond reasonable doubt that an entity has committed a relevant offence under the Companies Act 2006, using authority granted by the Economic Crime and Corporate Transparency Act 2023.10GOV.UK. Companies House Approach to Financial Penalties
A penalty can take the form of a fixed amount, a daily rate for each day the offence continues, or both. Companies House will typically issue a warning notice first, giving the entity 28 days to file corrected accounts before any penalty is imposed. The amount depends on factors including the seriousness of the offence, whether the entity has committed similar offences in the past five years, and any aggravating or mitigating circumstances. In more serious cases Companies House may pursue prosecution instead of a financial penalty.10GOV.UK. Companies House Approach to Financial Penalties
The most common classification mistake is a growing entity that continues to file micro-entity accounts under FRS 105 after breaching the size thresholds for two consecutive years. If you are close to a boundary, check the thresholds at each reporting date, particularly now that the 2025 threshold increases may have changed your classification in either direction.