This guide is based on UK law. It was last updated in August 2018.

Firms involved in anti-competitive behaviour may find their agreements to be unenforceable and risk being fined up to 10% of group global turnover for particularly damaging conduct as well as exposing themselves to possible damages actions. Furthermore, individuals could also find themselves facing director disqualification orders or even criminal sanctions for serious breaches of competition law (see Out-Law's guide to Individual liability for competition law infringements).

As such, any business - whatever its legal status, size and sector - needs to be aware of competition law, firstly so that it can meet its obligations (and in doing so, avoid the penalties mentioned above), but also so it can assert its own rights and protect its position in the marketplace.

In the UK two sets of competition rules currently apply in parallel. Anti-competitive behaviour which may affect trade within the UK is specifically prohibited by Chapters I and II of the Competition Act 1998 and the Enterprise Act 2002. Where the effect of anti-competitive behaviour extends beyond the UK to other EU Member States, it is prohibited by Articles 101 and 102 of the Treaty on the Functioning of the European Union (TFEU).

UK and EU competition law prohibit two main types of anti-competitive activity:

  • anti-competitive agreements (under the Chapter I / Article 101 prohibitions); 
  • and abuse of a dominant market position (under the Chapter II / Article 102 prohibitions).

The UK government has said it will make no fundamental changes to its competition law regime after the UK leaves the EU. Even after Brexit, or after any transition period, UK companies whose activities may affect trade within the EU, will remain subject to EU competition law.

Anti-competitive agreements (Chapter I / Article 101)

Both UK and EU competition law prohibit agreements, arrangements and concerted business practices which appreciably prevent, restrict or distort competition (or where this is the intended result) and which affect or may affect trade within the UK or the EU respectively.

Consequences of breach

Contravention of Chapter I or Article 101 can have serious consequences for a company:

  • firms engaged in activities which breach these provisions can face fines of up to 10% of group global turnover;
  • provisions in agreements which breach Chapter I or Article 101 are void and unenforceable (which may lead to the entire agreement being unenforceable);
  • firms in breach of Chapter I or Article 101 also leave themselves exposed to actions for damages from customers and competitors who can show they have been harmed by the anti-competitive behaviour; and
  • breach of Chapter I can result in individuals being disqualified from being a company director and lead to criminal sanctions.

Types of agreement caught

Whether an arrangement is anti-competitive is assessed on the basis of its objective, or its effect on competition, rather than its wording or form. This means that verbal and informal 'gentlemen's agreements' are equally capable of being found to be anti-competitive as formal, written agreements.

Examples of the types of arrangement which are generally prohibited under Chapter I and Article 101 include:

  • agreements which directly or indirectly fix purchase or selling prices, or any other trading conditions (for example, discounts or rebates, etc);
  • agreements which limit or control production, markets, technical development or investment (for example, setting quotas or levels of output);
  • agreements which share markets or sources of supply; and
  • agreements which apply dissimilar conditions to similar transactions, placing other trading parties at a disadvantage.


Cartel behaviour between competitors is the most serious form of anti-competitive behaviour under Chapter I or Article 101 and carries the highest penalties. A 'hardcore' cartel is one which involves price-fixing, market sharing, bid rigging or limiting the supply or production of goods or services. Individuals prosecuted for a cartel may be liable to imprisonment for up to five years and/or the imposition of unlimited fines.


The fact that an agreement is restrictive of competition does not mean that it is automatically prohibited (unless it is a hardcore cartel, see above). It may be that an agreement which appears to fall within the prohibitions under Chapter I or Article 101 is excluded or exempted from the competition rules.

For example, an agreement which would otherwise be caught by Article 101 may be assumed to be harmless where the parties to it have market shares sufficiently low that there can be no real effect on competition or trade between Member States. The same principle is considered to apply, by analogy, to agreements otherwise caught by Chapter I. However, agreements which are deemed restrictive by object will almost always be found to infringe the competition rules.

Other agreements may, nonetheless, be exempted under a 'block exemption' – a group exemption, which automatically exempts agreements falling within its terms. Different block exemptions may apply depending on the nature of the agreement or the market sector concerned.

Each sets out certain criteria (for example, relating to the market share of the parties and the types of restriction contained within the agreement) which must be met in order for an agreement to be block exempted.

Even if an agreement does not fit squarely within a block exemption, it is still not automatically unlawful or unenforceable. An agreement may be individually exempted on the grounds that the restrictions of competition are outweighed by its beneficial effects.

For example, an agreement between two pharmaceutical companies to develop a new drug together as opposed to independently is likely to be subject to the Chapter I or Article 101 prohibition, as the two companies working together can be seen to reduce the number of products likely to be produced, by preventing each company from working on independent projects. However, the benefits for consumers resulting from such co-operation (i.e. more investment, leading to better drugs which reach the market faster), may be considered sufficient to off-set any anti-competitive effects.

Abuse of a dominant market position (Chapter II / Article 102 prohibition)

Both UK and EU competition law prohibit businesses with significant market power unfairly exploiting their strong market positions.

Consequences of breach

Contravention of Chapter II or Article 102 can have serious consequences for a company:

  • firms engaged in activities which breach these provisions can face fines of up to 10% of group global turnover;
  • conduct in breach of Chapter II or Article 102 can be stopped by court injunction;
  • firms in breach of Chapter II or Article 102 also leave themselves exposed to actions from third parties who can show they have suffered loss as a result of the anti-competitive behaviour; and
  • breach of Chapter II can result in individuals being disqualified from being a company director.

Type of behaviour caught

To be in a position of dominance, a business must have the ability to act independently of its customers, competitors and consumers. Establishing if a company is dominant requires a complex assessment of a number of elements but, as a general rule, if a business has a 50% market share there is a presumption that it is dominant. However, dominance has been found to exist where market share is as low as 40%.

Article 102 requires dominance in a substantial part of the European Union, but there is no requirement under Chapter II that a dominant position must be held in a substantial part of the UK, meaning that, in theory at least, dominance could be considered to exist in a fairly small area of the UK.

However, having a dominant position does not in itself breach competition law. It is the abuse of that position that is prohibited. Examples of behaviour that could amount to an abuse by a business of its dominant position include:

  • imposing unfair trading terms, such as exclusivity;
  • excessive, predatory or discriminatory pricing;
  • refusal to supply or provide access to essential facilities; and
  • tying (i.e. stipulating that a buyer wishing to purchase one product must also purchase all or some of his requirements for a second product from the dominant supplier).


There is no equivalent to the exemption for anti-competitive agreements, whereby a firm's conduct may be exonerated because of some compensating benefit. However, a dominant company may be able to show that it has an objective justification for otherwise abusive behaviour in certain circumstances.

For example, a company may refuse to supply to a particular customer based on its poor credit rating, which would amount to the protection of legitimate business interests and not, therefore, to abusive conduct under Chapter II or Article 102. It would only be when such behaviour goes beyond what is necessary to protect the business' interests that this would amount to abuse.

Enforcement of competition law

For as long as the UK remains a member of the EU, UK competition authorities and courts are empowered to apply and enforce the entirety of Articles 101 and 102 of the TFEU, in addition to their existing powers to enforce the Competition Act 1998. The CMA is the principal competition law enforcement authority in the UK, though there are a number of sectoral regulatory authorities with concurrent powers to enforce competition laws in their respective sectors (for example, OFGEM for the electricity sector and OFWAT for the water sector).

The CMA and regulated authorities with concurrent competition powers have significant powers to investigate suspected anti-competitive behaviour (including entering and searching business and private premises with a warrant) and to impose significant fines on businesses found to have infringed competition law. Criminal sanctions are also possible for the most serious breaches of competition law (see our guide to Individual liability for competition law infringements).

The risks associated with being a party to an anti-competitive agreement or abusing a dominant position are serious. In addition to the consequences already highlighted in this article (substantial fines, void and unenforceable agreements, damages actions and criminal sanctions for individuals in certain circumstances), a further key deterrent for businesses is the major disruption and damage to a company's reputation which arise from lengthy investigations or subsequent litigation from customers, competitors and consumers.

Achieving compliance

In view of the severe consequences of non-compliance, we recommend that businesses regularly review whether the company's practices and agreements comply with competition law. For any company (and especially any company with a significant share of the markets in which it is active), it is vitally important to promote an understanding amongst employees as to what type of behaviour is and is not permissible under competition law.

One practical way to promote an understanding of competition law amongst employees is for a company to devise and actively implement a competition compliance policy that is specifically tailored to that company. Not only does this minimise the risk of being non-compliant in the first place, but if a company is investigated for anti-competitive behaviour, evidence of a competition compliance policy may be taken into account by the CMA or the European Commission and could lead to a reduction in fine.