I-VMS licence condition requirements for under-12 metre fishing vessels registered in England
Guidance explaining the operational requirements for Inshore Vessel Monitoring Systems (I-VMS) under the fishing licence condition.
Important update - 11 June 2026
MMO is resuming the I-VMS programme, having reached an agreement with CLS UK Ltd (previously Fulcrum Maritime Systems Ltd), to supply type-approved devices to the under-12m English fleet. This decision has been made to ensure that all English vessels are fitted with type-approved devices that transmit positional data to the UK VMS Hub, in accordance with legal requirements of the licence condition.
In the meantime, our compliance and enforcement approach will remain measured and pragmatic. Our priority is to ensure fishermen can continue to operate safely and legally.
The full statement about this decision can be found on MMO’s news page.
Next steps
Eligible vessel owners must register for a Nemo device from CLS UK Ltd, which will be provided and installed at no charge to those who register by 11.59pm on Sunday 12 July 2026.
Details on how to do this will be posted and emailed to eligible vessel owners. More information can be found on the I-VMS guidance page.
This page provides guidance on the requirements of the licence conditions and your obligations.
Fishing vessel licence conditions
A licence condition came into force on 12 May 2025, requiring:
- All English under-12 metre vessels registered with a commercial fishing vessel licence must have a functioning MMO type-approved I-VMS device when undertaking a trip to sea.
- That the device is switched on and transmitting data to be received by the UK VMS Hub
- The device is not manually overridden or tampered with to prevent the transmission of data.
While industry adapts to the licence condition, we will take a measured approach to enforcement and work with fishers and suppliers to address any issues. If MMO detects any issues with your device, we will contact you and provide appropriate guidance. Any enforcement action will be conducted in line with the MMO Compliance and Enforcement Strategy.
Operational guidance
- The type-approved I-VMS device must be operational whenever the vessel goes to sea.
- If the device is battery or solar powered, you must ensure it is charged and has sufficient power for the duration of the trip to sea.
- Check the status of your device - you can do this by using a mobile app or web portal provided by your device supplier – see ‘checking your device and data’ section below.
- Any issues should be reported directly to the supplier if they cannot be resolved using the troubleshooting guides provided to you.
- MMO will inform fishers if issues with the device are detected. It is the fisher’s responsibility to act and contact their I-VMS device supplier.
Checking your device and data
I-VMS devices send positional data (latitude, longitude, speed, and course) and report device ID, date, time and changes in events such as battery status and data stored.
Data will transmit at regular intervals via GPRS which is a mobile phone signal to reduce transmission costs. If the I-VMS device is in an area that has no GPRS coverage, then the device will retain the generated data and transmit it all once a connection has been restored. This complies with the requirements of the licence condition.
It is your responsibility to conduct regular checks to ensure the continuing operational requirements of your I-VMS device(s). These should form part of a regular routine and take place before any trip to sea.
Check the power supply
Ensure your device is switched on your device and check the power supply is fully operational during trips to sea. If using a portable power bank, make sure it is charged prior to your trip and is connected to your device.
Transmit and check your I-VMS device data
Check your device is transmitting data correctly by accessing the data app or web portal provided by your supplier.
I-VMS device suppliers have provided either a mobile app or a web portal for you to track your own I-VMS data. As well as checking the status of your device, you will also be able to use this data to:
- View and evidence fishing patterns and activities at sea.
- Refine your efforts and business plans
- Use it as evidence in any compliance or conflict resolution.
Contact your supplier for support with login access and user guidance.
Data transmitted is accessible to all UK Fisheries Administrations and can be used to monitor compliance and inform evidence-based decision-making for fisheries management, as outlined in the I-VMS privacy notice in MMO’s personal information charter.
Mobile blackspots
We know there are areas in our waters where it won’t be possible to send a signal to demonstrate a vessel’s location in real time. Devices are capable of storing a cache of data and then transmitting that information when the vessel returns to an area with a strong signal. This ensures that I-VMS devices will provide a continuous location history.
Device troubleshooting
The user manual provided with your device may help identify issues using light indicators (LEDs). As a general guide, LEDs indicate power, faults, and battery levels.
If the device fails, you must contact the supplier at the earliest opportunity to log the issue and get an understanding of timescales for a fix.
Report issues to your supplier
The user manual provided with your device may help with any troubleshooting. If you are still unable to resolve any issues, report them to your supplier immediately. Your supplier may also contact you to make sure everything is working correctly.
If a device needs to be returned to the supplier for investigation, please discuss the process with your supplier to ensure you do not risk any damage or manual interference that could void your device warranty. Providing you have notified your supplier of any issue and arranged a fix, you may still go to sea.
If you have any further questions after contacting your supplier, you can also contact us by emailing ivms@marinemanagement.org.uk with details of the issue and the vessel it relates to.
Buying, selling and ownership changes
Buying a vessel
You must obtain a licence via our fishing vessel licensing process . You can also contact the I-VMS team for advice and support.
Buying a device
Fishers must choose a supplier, order the device and arrange installation. Devices must be installed and operational for any trip to sea. Guidance on the steps to take can be found on the type approved devicesguidance page.
Selling a vessel
You must notify MMO if you are selling a vessel as part of the licensing process. If you are selling a vessel with an I-VMS device installed, you may be able to:
- Retain ownership of the device and install it on another under-12 metre vessel
- Transfer ownership of the I-VMS device to the new vessel owner.
It is the owner’s responsibility to notify their I-VMS supplier of their intentions. Any transfer will be dependent on the agreement with the device supplier. If a transfer of ownership is allowed, the I-VMS device will need to be cleared of existing data before the new owner can use it. This is in accordance with data protection and GDPR legislation – and is why the original device owner needs to make the request.
Sellers with I-VMS devices funded through an EMFF grant that has been installed for less than three years, must also inform the MMO grants team.
New vessels
All new vessels must be registered with the UK Ship Register and obtain a licence before installing an I-VMS device.
A new vessel must have an operational I-VMS device, that transmits positional data to the UK VMS Hub, prior to going to sea. Full details on type-approved devices and how to order can be found on the type-approved I-VMS devices page of gov.uk.
Frequently Asked Questions
Please read our updated updated FAQs for further information.
Contact us
Our dedicated helpline is open Monday to Friday, 9am to 5pm, by calling 01900 508618, or you can email our I-VMS Engagement and Support team at ivms@marinemanagement.org.uk.
Updates to this page
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The 'important information' section has been updated to alert industry of the next stage in the I-VMS programme.
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Updated notice with advice for fishermen relating to I-VMS device data transmissions
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Information box updated with information about Devon & Severn IFCA temporary measures in response to ceased I-VMS data transmissions by Succorfish to the UK VMS Hub.
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Updated information to provide clarity on the selling of vessels with I-VMS devices and returning devices to suppliers for investigation / repairs
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Guidance updated to reflect that a licence condition is now in force for the use of I-VMS devices on licensed English vessels, under-12 metres in length, undertaking a trip to sea.
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First published.