If your vessel is already registered with the UK Ship Register, you can apply to update your registration details online to change:
Details of the vessel e.g. tonnage. If tonnage has changed confirmation such a ITC69 or Certificate of Survey for Tonnage and Measurement will be required
To register a change of details via email or post (details provided below), provide a copy of a signed letter from the owner confirming the change of details.
Apply by post
UK Ship Register (The Registry of Shipping and Seamen)