TTM03160 | Qualifying companies and ships: Person to whom chartered is not a third party
From HM Revenue & Customs · Tonnage Tax Manual
Bareboat charters-out
Bareboat charters-out (see TTM03150) are allowed in the regime if the charter is to another tonnage tax company in the same tonnage tax group. This relaxation of the general rule will cover the (common) situation where, for commercial reasons, a ship is owned by one member of a group but operated by another.
See also TTM13120: this relaxation also applies to ships chartered to a partnership of which the company is a partner.
'Double charge' to tonnage tax
If a ship is chartered from one group company to another in the same group, they will both be charged tax on the tonnage of the ship, see TTM01320.