Tonnage measurement of UK ships: Authorised organisations
Source: gov.uk (2025-08-06)

This webpage provides a list of organisations authorised under UK legislation to conduct tonnage measurement and issue certification on UK registered vessels.

1. Introduction and background

The following legislation provides the legal requirements for the measurement of a ship’s tonnage for registration purposes:

The Merchant Shipping Act 1995:

Section 10 - Registration regulations; (https://www.legislation.gov.uk/ukpga/1995/21/section/10)

Section 11 - Tonnage ascertained for registration to be tonnage of ship (https://www.legislation.gov.uk/ukpga/1995/21/section/11); and

Section 19 - Tonnage regulations (https://www.legislation.gov.uk/ukpga/1995/21/section/19);

The Merchant Shipping (Tonnage) Regulations 1997 (SI 1997 No. 1510):

Part II (https://www.legislation.gov.uk/uksi/1997/1510/part/II/made) - Application, Ascertainment of Tonnage and Certification for United Kingdom Ships of 24 Metres in Length and Over; and

Part III (https://www.legislation.gov.uk/uksi/1997/1510/part/III/made) - Application, Ascertainment of Tonnage and Certification for United Kingdom Ships of Less Than 24 Metres in Length, Other Than Fishing Vessels;

The Merchant Shipping (Registration of Ships, and Tonnage) (Amendment) Regulations 1999 (SI 1999 No. 3206); (https://www.legislation.gov.uk/uksi/1999/3206/contents/made) and

The Merchant Shipping (Fishing Vessels – Tonnage) Regulations 1988 (SI 1988 No.1909) (https://www.legislation.gov.uk/uksi/1988/1909/contents/made) (Apply to fishing vessels under 24 m length).

The legislation also requires that the person undertaking tonnage measurements satisfies the requirements set out by the MCA.

Recognised Organisations (ROs) are those organisations the UK has recognised to comply with its international obligations in relation to the International Maritime Organisation’s (IMO) Code for Recognised Organisations.

Small commercial vessel (SCV) Certifying Authorities (CAs) are those organisations the UK has authorised to examine and certificate SCVs in accordance with the requirements of the following legislation:

The Merchant Shipping (Small Workboats and Pilot Boats) Regulations 2023 (https://www.legislation.gov.uk/uksi/2023/1216/contents/made)(SI 2023 No.1216 as amended); and

The Merchant Shipping (Vessels in Commercial Use for Sport or Pleasure) Regulations 1998 (https://www.legislation.gov.uk/uksi/1998/2771/contents) (SI 1998 No. 2771 as amended).

Fishing Vessel Certifying Authorities (FVCAs) are those organisations the UK has authorised to examine and certificate small fishing vessels in accordance with the applicable requirements of the following legislation and codes:

The Fishing Vessels (Codes of Practice) Regulations 2017 (https://www.legislation.gov.uk/uksi/2017/943/contents);

The Merchant Shipping (Registration of Ships) Regulations 1993 (https://www.legislation.gov.uk/uksi/1993/3138/contents)

MSN 1871 (https://www.gov.uk/government/publications/msn-1871-amendment-no-2-f-the-code-of-practice-for-the-safety-of-small-fishing-vessels-of-less-than-15m-length-overall) as maybe amended, (The Code of Practice for the Safety of Small Fishing Vessels of less than 15m Length Overall);

MSN 1872 (https://www.gov.uk/government/publications/msn-1872-amendment-1-safe-working-for-construction-and-use-of-fishing-vessels) as maybe amended, (The Code of Safe Working Practice for the Construction and Use of Fishing Vessels of 15m Length Overall to less than 24m Registered Length)

MGN 630 (https://www.gov.uk/government/publications/mgn-630-f-amendment-3-pre-registration-surveys-for-fishing-vessels) - FISHING VESSELS: Pre-Registration surveys for Fishing vessels of less than 15m Length Overall built before 16 July 2007 and existing vessels of 15m Length overall to less than 24m Registered Length wishing to join the UK Register

ROs are authorised to undertake tonnage measurement of all UK ships.

SCV CAs are authorised to undertake tonnage measurement of ships under 24 metres in length excluding fishing vessels. SCV CAs are also authorised to undertake tonnage measurement of pre-ITC’69 vessels (keel laid before 21st July 1968) of less than 150 tons but 24m in length or over.

FVCAs (https://www.gov.uk/guidance/fishing-vessel-certifying-authorities) can be authorised to undertake tonnage measurement of fishing vessels under 24 metres in length.

2. Authorised Organisations to measure tonnage by vessel type and length

*Note: Class NK is not authorised for tonnage measurements of fishing vessels

3. List of Tonnage Authorities

The following is a list of the offices of Recognised Organisations and Certifying Authorities authorised by the MCA as ‘Tonnage Authorities’ through formal agreement to undertake tonnage measurement of UK ships:

Recognised Organisations (ROs)

American Bureau of Shipping Europe Ltd

Eagle House10 Berrymoor CourtNorthumberland Business ParkCramlingtonNE23 7RZ

Tel: xx-xxxx-xxxx

Email: xxx@xxx.xx (mailto:xxx@xxx.xx)

Bureau Veritas Marine & Offshore

Suite 1 and 2Keel HouseTyne DockSouth ShieldsTyne and WearNE34 9PY

Tel: xx-xxxx-xxxx

Email: xxx@xxx.xx (mailto:xxx@xxx.xx)

Class NK

Nippon Kaiji KyokaiLeaf C, Tower 4225 Old Broad StreetLondonEC2N 1HQ

Tel: xx-xxxx-xxxx

Email: xxx@xxx.xx (mailto:xxx@xxx.xx)

DNV-GL Maritime

24 Steel House4300 ParkwaySolent Business ParkWhiteleyHampshirePO15 7FP

Tel: xx-xxxx-xxxx

Email: xxx@xxx.xx (mailto:xxx@xxx.xx)

Lloyd’s Register EMEA

Global Technology CentreHampshire HouseHampshire Corporate ParkSouthamptonSO53 3RY

Tel: xx-xxxx-xxxx

Email: xxx@xxx.xx (mailto:xxx@xxx.xx)

Web: https://www.lr.org/en/contact-us/

RINA UK Ltd

North Wing,1st Floor2 Charlotte PlaceSouthamptonHampshireSO14 0TB

Tel: xx-xxxx-xxxx

Email: xxx@xxx.xx (mailto:xxx@xxx.xx), xxx@xxx.xx (mailto:xxx@xxx.xx)

Web: https://www.rina.org/en/business/marine

Small Commercial Vessel Certifying Authorities (SCV CAs)

International Institute of Marine Surveying

Murrills House48 East StreetPortchesterPO16 9XS

Tel: xx-xxxx-xxxx

Email: xxx@xxx.xx (mailto:xxx@xxx.xx)

MECAL Ltd

Office 1BrooklandsBudshead RoadPlymouthPL6 5XR

Tel: xx-xxxx-xxxx

Email: xxx@xxx.xx (mailto:xxx@xxx.xx)

Royal Yachting Association

RYA HouseEnsign WayHambleSouthamptonSO31 4YA

Tel: xx-xxxx-xxxx

Email: xxx@xxx.xx (mailto:xxx@xxx.xx)

Society of Consulting Marine Engineers and Ship Surveyors

Ground FloorUnit 5, Prospect House7 Ocean WaySouthamptonSO14 3TJ

Tel: xx-xxxx-xxxx

Email: xxx@xxx.xx (mailto:xxx@xxx.xx)

Email as FVCA: xxx@xxx.xx (mailto:xxx@xxx.xx)

Yacht Designers and Surveyors Association

The Glass Works3b Penns RoadPetersfieldHampshireGU32 2EW

Tel: xx-xxxx-xxxx

Email: xxx@xxx.xx (mailto:xxx@xxx.xx)

4. More information

For more information or to apply to act as a Tonnage Authority, please contact:

External monitoring and assurance

Maritime and Coastguard AgencyBay 3/07Spring Place105 Commercial RoadSouthamptonSO15 1EG

E-mail: xxx@xxx.xx (mailto:xxx@xxx.xx)