UK Marine Licence Explained: Who Needs One, Who Grants It and What It Costs

If you are about to put anything in the sea, or take anything out of it, work through the quick-check table first and confirm with the MMO before you start. That one habit avoids the commonest mistake: assuming an exemption applies without meeting every condition of it. A marine licence is the permission the law requires before most work on, in or over the sea bed around the UK. The rules sit in one Act, but the body that issues the licence depends on the waters, and a licence is only one of several consents a project can need. The UK marine licensing hub lists the rest of the series.

What a marine licence is

A marine licence is a consent granted under the Marine and Coastal Access Act to allow licensable marine activities to be carried out¹². Section 65 of the Act is blunt about the requirement: no person may carry on a licensable marine activity, or cause or permit another person to carry one on, except in accordance with a licence granted by the appropriate licensing authority⁴. A few activities are exempt from that rule, and the exemptions are set out separately⁴.

The Act itself created the Marine Management Organisation (MMO), which licenses, regulates and plans marine activity in English waters and Northern Ireland offshore waters; in Wales that job belongs to Natural Resources Wales^{8, 15, 19}. The MMO is an executive non-departmental public body sponsored by the Department for Environment, Food & Rural Affairs¹⁵. For the full story of the regulator, see the Marine Management Organisation.

Quick check: do I need a marine licence?

For a small job, start with this table. It is a guide, not a ruling: you must meet every condition of an exemption, notify the MMO where required and hold any other consent¹⁷. The exemptions come from the Marine Licensing (Exempted Activities) Orders 2011, 2013 and 2019¹⁷.

When none of these fits, or you are unsure, use the MMO’s Get permission for marine work service: checking is your responsibility before you start¹. The list above follows the MMO’s exemptions guidance as published on 18 November 2025¹⁷.

Which activities need a marine licence

The Act defines 13 licensable marine activities in section 66¹². In plain terms they cover putting things into the sea or onto the seabed, sinking vessels, building, removing and dredging, explosives and incineration at sea^{5, 12}. Three of them matter most for anyone thinking about seabed minerals.

The law deliberately defines dredging widely: it includes using any device to move any material, whether or not suspended in water, from one part of the sea or sea bed to another part⁵.

Who grants the licence

The licensing authority depends on the waters. Section 66 defines the UK marine licensing area as the UK marine area other than the Scottish inshore region, so Scottish inshore waters sit outside it⁵.

Section 66 of the Act defines the UK marine licensing area as the UK marine area other than the Scottish inshore region, which is why Scottish inshore licences come under Scottish legislation instead^{5, 18}. Welsh exemptions sit in a separate Welsh order, with its own 2026 amendment²⁰.

The seabed has a landowner as well as a regulator, and its consent is separate. See the Crown Estate’s seabed rights for how the two fit together.

How the application works

An application starts with an account on the MMO’s online system². The MMO’s application guidance sets out the sequence. In order:

1. Register on the MMO's online system and set up an online account².
2. The MMO validates the application².
3. You are told the payment band or fee estimate and have 14 days to accept it or pay².
4. Once the application is validated, the MMO aims to allocate it within 7 days and start the process².
5. The MMO may consult interested parties². You must advertise the proposed works, and a public consultation starts when the notices are published¹².
6. The MMO aims to decide most applications within 13 weeks of validation. Some take longer².

Some low-risk activities may qualify for self-service marine licensing, and some low-volume dredging for the accelerated licensing process². The public register is open without an account: it shows applications and licences, and it lets anyone make a representation on an application in consultation¹⁵.

Having your say on someone else’s application

Anyone can respond. A representation must be received within 28 days of the date of the first notice¹². The register holds marine licence applications and decisions, including marine minerals extraction and renewable energy documents¹². The MMO runs a stakeholder and public consultation for all standard applications, but not for self-service ones¹².

What it costs

The published fee schedule charges for the time the MMO and the Centre for Environment, Fisheries and Aquaculture Science (Cefas) spend on the case³. Cost depends on the band your project falls into.

The cheapest route is self-service (band 1): a licence costs £50, payable in advance³. At the other end, any band 2 project with complex characteristics moves to band 3³. A project estimated to cost more than £1 million, or one that cannot give a confident cost estimate, counts as complex, as does part of a project that needs an environmental impact assessment³. Where one application covers several licensable activities in different fee bands, the higher band is payable³.

These figures are from the MMO fee page updated on 29 July 2026³. Fees in Wales are set by Natural Resources Wales in its own bands¹⁹.

Billing follows time rather than the quote. Final charges are based on actual hours, not on the original estimate, and time is charged in units of 15 minutes with a minimum of 15 minutes for each item of work². MMO advice is charged at £122 per hour³.

Monitoring has its own price. For a licence processed as a band 2a or 2b application, the monitoring fees are capped at £750 for all monitoring activities for the duration of the licence³. A band 3 licence gets two monitoring inspections a year³. For a closer look, see marine licence fees in England.

Seabed minerals, dredging and removal

Aggregate dredging, the removal of sand and gravel from the seabed for use in construction, always requires a marine licence¹⁰. Smaller maintenance dredging has a ladder of volumes:

• under 500 cubic metres may be exempt from needing a licence¹⁰;
• 500 to 1500 cubic metres may suit accelerated licensing¹⁰;
• over 1500 cubic metres may need a standard marine licence¹⁰.

Dredging is classed as capital or maintenance. Capital dredging goes to a depth that has not been dredged in the last 10 years¹⁰. Removal of any substance or object from the seabed with a vessel needs a licence in English waters and Northern Ireland offshore waters¹¹.

Minerals sit in the same system. The public register carries marine minerals extraction documents alongside renewable energy ones¹². The Crown Estate, as seabed landowner, adds its own layer: beyond 12 nautical miles, survey activity needs a Crown Estate seabed survey licence where it relates to an activity over which the Crown Estate holds rights, such as offshore renewable energy, marine mineral extraction, or gas and carbon storage¹³. Aggregate dredging has its own page in marine aggregate dredging in the UK.

The Crown Estate’s seabed survey licence

A seabed survey licence (SSL) covers small, temporary survey activity that touches the seabed¹³. Licences last up to 12 months¹³. Within the 12 nautical mile limit, all survey activity that interacts with the seabed requires an SSL, unless the works fall within the public rights of navigation or fishing¹³. The standard application fee is £500, with a concessionary rate of £100¹³, and issuing a licence of this kind can take the Crown Estate around 6 weeks¹³. The Crown Estate is also a separate step from the MMO: an SSL is listed among the permissions to seek elsewhere¹.

How the licensing authority decides

The Act gives the authority three options on an application: grant the licence unconditionally, grant it subject to the conditions the authority thinks fit, or refuse it⁶. A licensing authority must not grant a licence for any activity that is contrary to international law⁶.

In England the decision weighs the environment, which includes sites of historic or archaeological interest as well as natural habitats and species². The conditions it attaches are typically used to limit harm to the environment, human health and other legitimate uses of the sea². They can also require the removal of any object or works at the end of a specified period⁶.

Environmental assessment and protected sites

The Marine Works (EIA) Regulations 2007 require certain projects with the potential to affect the environment significantly to submit an Environmental Impact Assessment before a licence decision is made⁹. Applicants must also complete a Marine Plan Policy Assessment, and there are 11 marine plan areas in England⁹. Parts of the marine area are protected in law, including Marine Conservation Zones, European protected sites and the habitats of protected species⁹. A project that needs an assessment is treated as a complex case for fees³.

After the decision: conditions, variations and appeals

Failing to comply with a condition is a breach of the licence². A request to vary a licence should be made at least 3 months before the change is required, or 3 months before the licence end date².

Only the applicant can appeal a decision². In England appeals are heard by the Planning Inspectorate on behalf of the Secretary of State, and the applicant has 6 months from the date of the decision to notify it². In certain circumstances the MMO can ask ministers whether they want to hold a public inquiry and then decide an application themselves².

Other permissions that may also be needed

A marine licence does not replace other consents. A site of special scientific interest nearby may call for consent from Natural England². Works partly on land often need planning permission². A separate marine wildlife licence is needed if an activity may kill, capture or disturb protected species or habitats¹. The Crown Estate’s seabed survey licence is another¹. Anyone who has told the MMO about an exempt activity after 18 November 2025 uses the Get permission for marine work service¹.

Penalties

Carrying on a licensable activity without a licence is an offence, and so is failing to comply with any condition of a licence⁷. On summary conviction the fine can be as high as £50,000⁷. On conviction on indictment the penalty is a fine, imprisonment for up to two years, or both⁷.