Yes. They are governed by the Enterprise Act 2002 as amended by the Enterprise and Regulatory Reform Act 2013.
The Competition and Markets Authority ("CMA") has also published several guidances on thresholds and their procedures, and this guidance also provides a general outline and advice relating to the UK merger control regime. The CMA defines a merger as the change in the control in an enterprise, or the quality of control over another enterprise when the two enterprises cease to be distinct.

The CMA is the single UK competition authority, whose main aim is to promote competition both within and outside the UK for the benefit of the consumer. It examines completed and anticipated mergers. Some CMA decisions can be appealed to the Competition Appeal Tribunal ("CAT"). 

The Secretary of State may intervene in very strict circumstances if there is an “exceptional public interest”, such as national security, the freedom of the press or if the stability of the UK financial system is at risk provided the thresholds below are met, or if they are not met when the merger involves newspapers or broadcaster and certain government contractors. The thresholds for certain strategic industries were lowered in 2018 to allow for the review of transactions involving military or dual-use technologies, multi-purpose computing hardware and quantum technology. 

The European Commission has jurisdiction under the EU Merger Regulation where the merger has an “EU dimension”. There are provisions in the EU legislation that allow for mergers caught by the UK regime to be referred “up” to Brussels and for mergers with an EU dimension to be referred “down” to the UK for review, but they are not automatic. The EU regime allows member states to step in to protect legitimate non-competition issues such as plurality of the media, public security and prudential rules applicable to financial institutions. 

No. There is no requirement to file. However, the rules are set out in the guidance notes and in the Merger Notice form. 

There are two relevant merger situations which can trigger UK merger rules. These thresholds occur where two or more enterprises cease to be distinct and either (i) the UK turnover of the target company exceeds £70 million (the turnover test), or (ii) the merger creates or enhances a share of supply of 25 percent or more of goods and services in the UK, or a substantial part of it (the share of supply test).

The regime allows for parties to a de minimis merger to request that a file is not opened. If one is opened, then at the end of phase 1 the parties have the opportunity to ask the CMA not to refer based on the turnover of the market affected. 

Certain sector-specific rules also exist. A few of the major ones include the newspaper sector, water and sewage, railways, banks and building societies, television and radio broadcasters, the health sector and defense. In June 2018 a new lower threshold was introduced in relation to national security mergers, which applies to activities in connection with quantum software, computer hardware, and military/dual-use items.  
 

No. Notification is not required in advance for clearance for any investment. However, a merger situation may exist even when a minority investment is made, allowing the CMA to commence an inquiry or the parties to voluntarily notify. 

Yes. The Enterprise Act provides that an enforcement order may apply to foreign-to-foreign transactions if either of the companies are carrying on business in the UK, including if they are in partnership with one or more others in the UK. 

The turnover test and share of supply test detailed above are the relevant thresholds for notification. However, it should be noted that the UK has a voluntary notification procedure. 

The UK has a voluntary notification procedure. 

If companies decide to seek clearance from the CMA, the recommended procedure to follow takes place in three stages. First, they should seek advice on a confidential basis prior to any announcement - this tends to be an informal arrangement. Then the companies should enter into pre-notification discussions with the CMA. The CMA’s guidance states that, in general, pre-notification contact should commence at least two weeks before the parties’ intended date of notification. In many cases, a significantly longer period is appropriate and is encouraged by the CMA. The final step is to provide notification by filing a Merger Notice. 

Once the CMA is sufficiently aware that a merger situation has occurred it has the opportunity to open up an investigation for up to four months thereafter. 
 

No. The CMA has the power to prevent any further intervention and in exceptional circumstances, it can require that merger arrangements are rolled back to the previous state of affairs before the transaction took place. 

Notification is made by completing a Merger Notice and submitting it to the CMA – either in the standard template format or in a format agreed by the parties with the CMA. The merger must be in the public domain in order for a merger notice to be submitted. 

Yes. It is payable in all cases where the CMA publishes either a reference decision or a decision not to make a reference at the end of the preliminary (Phase 1) inquiry (if undertakings are offered to avoid an in-depth investigation the fee is payable once the undertakings are accepted by the CMA). An invoice is issued and must be paid within 30 days. There are some exemptions for the filing fee such as for small and medium-sized enterprises. The fee depends on the size of the target company’s UK turnover and is as follows:

• £40,000 where the turnover is £20 million or below;
• £80,000 where the turnover is over £20 million but not over £70 million;
• £120,000 where the turnover is over £70 million but not over £120 million; and
• £160,000 where the turnover exceeds £120 million.
   

The review process undertaken by the CMA may be split into two stages – Phase 1 and Phase 2. Phase 1 consists of an initial review from which three decisions may be reached: (i) an unconditional clearance; (ii) a clearance subject to legally binding undertakings; or (iii) reference for a Phase 2 investigation. 

The Phase 1 assessment period is 40 working days from the first working date after the CMA accepts the Merger Notice is complete or the first working day after the CMA confirms it has sufficient information to conduct its investigation. The period can be extended by consent (up to a maximum of 20 additional working days) to discuss undertakings in lieu of phase 2, where a reference is made to the EU or in circumstances where the CMA’s requests for information have not been complied with by the parties or third parties. There are special rules for fast track of mergers to a phase 2 in the UK and for “creeping mergers” where there are a series of acquisitions that have taken place. 

Between phase 1 and phase 2 there can be a pause of up to two weeks. 

Phase 2 consists of a full investigation by the CMA, who are given a statutory period of 24 weeks to conduct an investigation and publish a report (subject to certain statutory rights to extend or stop the clock). The CMA may extend this period by up to 8 weeks at their discretion. The investigation consists of both written submissions from both parties to the transaction and any interested third parties, and oral hearing with the parties to the transaction as well as third parties with significant interest. If remedies are to be ordered or accepted the CMA has a further 12 weeks to agree to those remedies. 
 

The substantive test is whether a merger has resulted, or is expected to result, in a substantial lessening of competition in a market in the UK for goods and services (this does not take into account the powers that the Secretary of State has to intervene in the limited circumstances set out above). 

There are three potential scenarios where mergers can lead to a substantial lessening of competition:

• Unilateral effects – Where two competing firms remove any rivalry between them in a horizontal agreement, allowing the newly merged firm to raise prices in order to make a greater profit.  
• Coordinated effects – Potential to arise in both horizontal and non-horizontal mergers. This is when the merger allows for several firms within the market (including the merged firm) to raise their prices because the merger makes it easier for these firm to co-ordinate. 
• Vertical or conglomerate effects – Potential to arise primarily in non-horizontal mergers, where the merged firm has a strengthened ability to use its market power to reduce rivalry.
   

Three decisions may be reached from a Phase 1 assessment: (i) an unconditional clearance; (ii) a clearance subject to legally binding undertakings; or (iii) reference for a Phase 2 investigation.

Similarly, one of three decisions can be given after a Phase 2 investigation: (i) unconditional clearance; (ii) conditional clearance subject to legally binding undertakings; or (iii) prohibition. 

In the phase 1 process, it is for the parties to submit undertakings but in phase 2 the CMA typically takes the lead. 
 

Yes. Broadly speaking the CMA splits remedies into (i) Structural Remedies - such as prohibition of the proposed merger; divestment of a completed acquisition; partial prohibition or divestment of parts of the business, particular assets or rights; or dismantling exclusive distribution agreements); and (ii) Behavioural Remedies - such as intellectual property remedies and controlling outcomes – for example by introducing price caps or other restraint on prices; or an obligation to increase the transparency of prices. The CMA tends to favor structural remedies over behavioral remedies. 

There are no sanctions, as such.  If a transaction meets the thresholds and the parties elect not to notify, the CMA may open its own investigation. 

A merger may be implemented before clearance unless it has been referred for a Phase 2 investigation. The CMA may apply a fixed penalty (capped at 5 percent of the turnover of the company fined) for failure to comply with any interim measures.  

Yes. The CMA can review and/or investigate mergers where the parties do not seek prior clearance. The CMA has a duty to monitor merger activity in the event that an unnotified merger leads to a significant lessening of competition. 

The CMA has an intelligence function which monitors all unnotified merger activity. If a merger has been completed and there has been no notification, the CMA may require the termination of a completed transaction or the rollback or cessation of any further integration. The CMA will investigate a merger if it suspects it is within its jurisdiction and subject to a payable fee.

Recently, the CMA has undertaken a much larger focus on digital markets and the potential anti-competitiveness of mergers taking place in this rapidly growing industry. It is also preparing for the UK’s exit from the EU and is looking at implementing changes in order to adapt to this. 

It is expected that the European Commission will no longer take any UK cases into its own hands post-Brexit and so British authorities and courts will be in charge of all decisions affecting UK markets after this date. It is expected that significantly more transactions will be notified to the CMA once the UK leaves the EU.