9Amount of employment income charged to taxU.K.
(1)The amount of employment income which is charged to tax under this Part for a particular tax year is as follows.
(2)In the case of general earnings, the amount charged is the net taxable earnings from an employment in the year.
(3)That amount is calculated under section 11 by reference to any taxable earnings from the employment in the year (see section 10(2)).
(4)In the case of specific employment income, the amount charged is the net taxable specific income from an employment for the year.
(5)That amount is calculated under section 12 by reference to any taxable specific income from the employment for the year (see section 10(3)).
(6)Accordingly, no amount of employment income is charged to tax under this Part for a particular tax year unless—
(a)in the case of general earnings, they are taxable earnings from an employment in that year, or
(b)in the case of specific employment income, it is taxable specific income from an employment for that year.