Guidance

Supplementary pages CT600F: Tonnage Tax

If the company operates ships, check how to complete supplementary pages CT600F and what information you need to include.

When to complete

Complete these supplementary pages if the company operates ships and is a party to a Tonnage Tax election.

Company information

F1 Company name

Enter the company name.

F2 Tax reference

Enter the company’s 10-digit Unique Taxpayer Reference.

Period covered by this supplementary page (cannot exceed 12 months)

F3

Enter the start date using the format DD MM YYYY.

F4

Enter the end date of the accounting period using the format DD MM YYYY.

Part 1: Tonnage Tax information for this period

F5A and F5B The company was a party to a Tonnage Tax group election

Enter X in the relevant box. If Yes (F5A) complete box F10. If No (F5B) complete box F15A or box F15B.

Tonnage Tax group election must be made jointly by all qualifying companies in the group.

F10 Name of the Tonnage Tax group of which the company was a member at the end of the accounting period

Enter the name of the group.

The qualifying companies in a group may nominate one group company to deal with matters concerning Tonnage Tax that are more conveniently dealt with on a group-wide basis. This includes the 75% limit on chartered-in tonnage.

Where a group wishes to make such an arrangement, all qualifying companies should jointly sign a letter nominating one of the companies as the representative company and specifying the matters that it will handle on behalf of the whole group.

F15A and F15B Training commitment

Enter X in the relevant box.

A company or group electing into Tonnage Tax (or renewing its election) must have a current certificate from the Department for Transport confirming approval of its initial or annual training commitment.

F20A to C and F25A to C Chartering-in limit

Enter X in the relevant boxes.

Not more than 75% of the net tonnage of the company’s qualifying vessels should relate to ships that are chartered in, other than on bareboat terms. For groups, the 75% limit relates to the net tonnage of qualifying ships in the group, ignoring chartering between group members.

As ships will often be operated for less than a full accounting period, the percentage will need to be computed by reference to the aggregate daily net tonnage for the company or group. Read paragraphs 37 to 40 of Schedule 22 to the Finance Act 2000 for more information on the 75% limit.

F30A to C The company or group operated ships that were not registered in the UK for the first time

Enter X in the relevant box. Complete box F30C if the period covered by the return relates entirely to excepted years.

Flagging rules have been repealed with effect from 1 April 2022. Do not complete boxes F30A and F30B, complete box F30C if the return period start date is on or after 1 April 2022.

Read section 25(7) to the Finance Act 2022 for more information.

F35A and F35B The company or group satisfied the flagging conditions

Enter X in the relevant box. You should only complete this section if you completed box F30A.

Flagging rules have been repealed with effect from 1 April 2022. Do not complete boxes F35A to F35B if the return period start date is on or after 1 April 2022.

Read section 25(7) to the Finance Act 2022 for more information.

F40A and F40B Offshore activities

These activities cover the exploration or exploitation of the seabed, subsoil, or natural resources in the UK sector of the continental shelf.

They do not apply to offshore supply vessels, tugs, anchor-handling vessels, and tankers:

  • unless they are dedicated to a particular oil field
  • where the company’s ships are engaged on offshore activities for a period that does not exceed 30 days in total

Part XI of Schedule 22 to the Finance Act 2000 applies only to companies that have vessels engaged in offshore activities in the UK sector of the continental shelf and which are not excluded under paragraph 105 of schedule 22.

Part 2: offshore training allowance

F45 and F50 Training allowance (offshore)

A company that falls within part XI of Schedule 22 to the Finance Act 2000 is allowed to offset the cash equivalent of training or any payments in lieu of training against its Corporation Tax liability on its profits from offshore activities.

The cash equivalent is based on the current rate of payments in lieu of training. The deduction is the sum of the cash equivalent amounts of training undertaken and any payments in lieu of training made, relating to days on which each ship was engaged in offshore activities in the UK sector.

Insert the amount in box F45 in box 450 of your CT600 form.

Part 3 : relevant shipping profits

Provide the following additional information about relevant shipping profits to assist HMRCs administration of Tonnage Tax.

F55A and F55B The profit or loss in the company’s accounts.

Do not include:

  • other non-tonnage tax profits or losses included elsewhere on form CT600
  • any amounts entered in boxes F60A, F60B or F65

A qualifying ship is operated by a company when it is owned by or chartered to that company. It is not regarded as operated where it is bareboat chartered-out, unless to a fellow group member, or to the Crown, or where there is short-term over-capacity and the charter does not exceed 3 years.

F60A and F60B The profit or loss in the company’s accounts in respect of the disposal of Tonnage Tax assets, which would otherwise be computed under chargeable gains rules

Profits are calculated by multiplying the daily profit for each ship by the number of days that each was operated during the accounting period.

The daily profit is calculated in units of 100 net tons at the following rates:

  • 100 net tons up to 1,000 — £0.60
  • 100 net tons from 1,001 to 10,000 — £0.45
  • 100 net tons from 10,001 to 25,000 — £0.30
  • 100 net tons above 25,000 — £0.15

Example

The following table shows how the daily profit for a ship of 30,099 net tons would be calculated.

Tons 100 ton units Rate Total
up to 1,000 10 £0.60 £6.00
from 1,001 to 10,000 90 £0.45 £40.50
from 10,001 to 25,000 150 £0.30 £45.00
above 25,000 50 £0.15 £7.50

In this case the total daily profit is £99.

No relief, deduction or set-off can be used to reduce the Tonnage Tax profits.

F65 Dividends and other distributions qualifying as relevant shipping income

Tonnage Tax profits replace relevant shipping profits. Broadly, these are the relevant shipping income from Tonnage Tax activities, including distributions from overseas shipping companies, plus chargeable gains on Tonnage Tax assets.

Tonnage Tax activities include core qualifying activities, qualifying secondary activities, and qualifying incidental activities. For more information read:

Part 4: computation of Tonnage Tax profits

Enter details of all qualifying ships.

F70 Computation of Tonnage Tax profits

A qualifying ship must be a seagoing ship of 100 gross tons or more used for the carriage of passengers or cargo, towage, salvage or other marine assistance or transport in connection with other services of a kind necessarily provided at sea.

Specifically excluded are:

  • fishing vessels
  • factory ships
  • pleasure craft
  • harbour or river ferries
  • offshore installations
  • tankers dedicated to a particular oil field
  • dredgers

Enter the amount from this box F70 in box 200 of your CT600 form.

More information

Read the Tonnage Tax Manual for more information.

Updates to this page

Published 30 September 2022
Last updated 2 January 2024 + show all updates
  1. Welsh translation added.

  2. We have updated the headings for F30 and F65.

  3. Information about the boxes to complete if the return period start date is on or after 1 April 2022 has been added to the the 'F30A to C The company or group operated ships that were not registered in one of the Member States' registers for the first time' and 'F35A and F35B The company or group satisfied the flagging conditions' sections.

  4. First published.

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