“…These include separate accounting for activities eligible and non-eligible to the scheme. Another measure consists of the "all or nothing options", requiring companies that are part of a group of undertakings to make the choice of entering jointly the scheme for all their eligible activities, or staying completely outside the benefits of the scheme -to avoid that firms choose the vessels based on their profitability (Werner, 2016). The Guidelines also mention an obligation to remain in the tonnage tax schemes for a period of at least ten years, which prevents companies from switching from the tonnage tax scheme to the general corporate income tax scheme when they suffer losses.…”