If section 678 applies, the taxable social security income for a taxable benefit for a tax year is F2the full amount of the social security income arising in the tax year, but subject to subsection (2).

That income is treated as relevant foreign income for the purposes of Chapters 2 and 3 of Part 8 of ITTOIA 2005 (relevant foreign income: remittance basis and deductions and reliefs).

See also Chapter 4 of that Part (unremittable income).