The deduction is available only against the net earnings
attributable to the eligible period.
The net earnings are amounts remaining after deductions
for:
The rule mainly affects cases where the eligible period covers only part of the tax year.
A seafarer has an eligible period ending on 5 November 2008. For
2008/09 he has earnings of £24,000 and pays pension
contributions of £2,400. His net earnings are £21,600.
The earnings attributable to the eligible period from 6
April 2008 to 5 November 2008 are £12,600 (7\12ths of
£21,600).
Liability for 2008/09 is calculated as follows:
| Earnings | £24,000 | |
| Pension | £2,400 | |
| Seafarers' deduction | £12,600 | |
| £15,000 | £15,000 | |
| Net taxable earnings | £9,000 |
Without this rule a person could effectively get relief for a full year's expenses, etc. against a part year's earnings. So in the example above there would have been a seafarers' deduction of £14,000 (7/12ths of £24,000) plus pension contributions of £2,400 leaving only £7,600 taxable.
