Ascension Island and Tristan da Cunha each have their OWN tax laws, entirely separate from Saint Helena's, despite sharing a single Governor and territory name. This is not one tax system but three. Residents on each island are taxed on their own island's basis.
The tax year is the calendar year across all three islands.
On Ascension Island, companies pay a flat 25% on chargeable income, with reduced rates for export, fishing, agriculture, and local manufacturing activities - notably, only 5 specifically named companies are taxed (at 18%), with all other companies taxed at 0%. Saint Helena and Tristan da Cunha have their own separate corporate tax structures under their respective local tax laws.
Saint Helena: 15% on the first GBP 6,000 of annual income, 27% above, with a GBP 3,500 tax-free personal allowance plus dependent allowances. Ascension Island: 21% on the first GBP 18,000, 26% above; dividends taxed at 8% for individuals (exempt for companies); capital gains at 10%. Military personnel on Ascension are exempt, as are short-term business visitors present no more than 7 days.
No VAT or GST applies on any of the three islands based on the sources reviewed.
Residency and tax liability are determined separately on each island given their genuinely separate tax law frameworks; presence-based tests generally apply, with specific exemptions for military personnel and short-term business visitors on Ascension Island.
A non-resident entity would have a permanent establishment on whichever specific island (Saint Helena, Ascension, or Tristan da Cunha) it maintains a fixed place of business or dependent agent, assessed separately under that island's own tax law given the tripartite structure.
No CFC-style attribution provision was found in the sources reviewed for any of the three islands, consistent with their small scale and simplified tax structures.
No statutory thin capitalization ratio or interest-limitation rule was identified in the sources reviewed.
None of the three islands use an elective check-the-box classification system or have a comprehensive ATAD2-style anti-hybrid regime.
No foreign bank account or foreign financial asset reporting regime exists on any of the three islands requiring residents to separately disclose foreign accounts.
No broad participation exemption was identified in the sources reviewed; Ascension Island's exemption of company dividends from further tax (see Personal Tax Rate above) is a narrower, specific provision rather than a full participation exemption regime.
No comprehensive foreign tax credit regime was confirmed in the sources reviewed for these islands specifically; confirm current provisions directly given the very limited public documentation available for jurisdictions of this scale.
These islands do not maintain a broad independent double tax treaty network given their British Overseas Territory status and very small scale; confirm any specific UK-mediated arrangement directly before relying on treaty relief.