Part I

Contributions

Preliminary

Outline of contributory system.
1
1
The funds required—
a
for paying such benefits under this Act or any other Act as are payable out of the National Insurance Fund and not out of other public money; and
b
for the making of payments under section 162 of the Administration Act towards the cost of the National Health Service,
shall be provided by means of contributions payable to the Inland Revenue by earners, employers and others, together with the additions under subsection (5) below and amounts payable under section 2 of the Social Security Act 1993.
2
Contributions under this Part of this Act shall be of the following ... classes—
a
Class 1, earnings-related, payable under section 6 below, being—
i
primary Class 1 contributions from employed earners; and
ii
secondary Class 1 contributions from employers and other persons paying earnings;
b
Class 1A, payable under section 10 below ... by persons liable to pay secondary Class 1 contributions and certain other persons;
bb
Class 1B, payable under section 10A below by persons who are accountable to the Inland Revenue in respect of income tax on
general earnings
in accordance with a PAYE settlement agreement;
c
Class 2, flat-rate, payable ... under section 11 below by self-employed earners;
d
Class 3, payable under section 13 or 13A below by earners and others voluntarily with a view to providing entitlement to benefit, or making up entitlement;
da
Class 3A, payable by eligible people voluntarily under section 14A with a view to obtaining units of additional pension; and
e
Class 4, payable under section 15 below in respect of the profits or gains of a trade, profession or vocation, or under section 18 below in respect of equivalent earnings.
3
The amounts and rates of contributions in this Part of this Act and the other figures in it which affect the liability of contributors shall—
a
be subject to regulations under sections 19(4) and 116 to 120 below; and
b
to the extent provided for by Part IX of the Administration Act be subject to alteration by orders made by the Treasury from year to year under that Part,
...
4
Schedule 1 to this Act—
a
shall have effect with respect to the computation, collection and recovery of contributions of Classes 1, 1A, 1B, , 3 and 3A, and otherwise with respect to contributions of those classes; and
b
shall also, to the extent provided by regulations made under section 18 below, have effect with respect to the computation, collection and recovery of Class 4 contributions, and otherwise with respect to such contributions, ....
5
For each financial year there shall, by way of addition to contributions, be paid out of money provided by Parliament, in such manner and at such times as the Treasury may determine, amounts the total of which for any such year is equal to the aggregate of all statutory sick pay , statutory maternity pay, statutory paternity pay, statutory adoption pay , statutory shared parental pay , statutory parental bereavement pay and statutory neonatal care pay recovered by employers and others in that year, as estimated by the Government Actuary or the Deputy Government Actuary.
6
No person shall—
a
be liable to pay Class 1, Class 1A , Class 1B or Class 2 contributions unless he fulfils prescribed conditions as to residence or presence in Great Britain;
aa
be treated under section 11(5B) as having actually paid Class 2 contributions unless he fulfils such conditions;
b
be entitled to pay Class 3 contributions unless he fulfils such conditions; or
c
be entitled to pay Class 1, Class 1A , Class 1B or Class 2 contributions other than those which he is liable to pay, except so far as he is permitted by regulations to pay them.
7
Regulations under subsection (6) above shall be made by the Treasury.
Words in s. 1(1) added (29.1.1993) by Social Security Act 1993 (c. 3), ss. 2(9), 5
Words in s. 1(1) substituted (25.2.1999 for specified purposes, 1.4.1999 in so far as not already in force) by Social Security Contributions (Transfer of Functions, etc.) Act 1999 (c. 2), s. 28(2)(a), Sch. 1 para. 5(2); S.I. 1999/527, art. 2(b), Sch. 2 (with arts. 3-6)
Words in s. 1(2)(b) omitted (with effect in relation to the tax year beginning with 6.4.2000 and subsequent tax years) by virtue of Child Support, Pensions and Social Security Act 2000 (c. 19), ss. 74(1), 86, Sch. 9 Pt. 8(1) (with s. 74(8))
Word in s. 1(3)(b) substituted (1.4.1999) by Social Security Contributions (Transfer of Functions, etc.) Act 1999 (c. 2), s. 28(3), Sch. 3 para. 1(2); S.I. 1999/527, art. 2(b), Sch. 2 (with arts. 3-6)
Words in s. 1(4)(b) repealed (25.2.1999 for specified purposes, 1.4.1999 in so far as not already in force) by Social Security Contributions (Transfer of Functions, etc.) Act 1999 (c. 2), s. 28(2)(a), Sch. 1 para. 5(3), Sch. 10 Pt. 1; S.I. 1999/527, art. 2(b), Sch. 2 (with arts. 3-6)
S. 1(7) inserted (1.4.1999) by Social Security Contributions (Transfer of Functions, etc.) Act 1999 (c. 2), s. 28(3), Sch. 3 para. 1(3); S.I. 1999/527, art. 2(b), Sch. 2 (with arts. 3-6)
Words in s. 1(6) inserted (8.9.1998 for specified purposes, 6.4.1999 in so far as not already in force) by Social Security Act 1998 (c. 14), s. 87(2), Sch. 7 para. 56(3); S.I. 1998/2209, art. 2(b)(c), Sch. Pts. 2, 3
Pts. 1, 6 modified (6.4.2001) by S.I. 2001/1004, regs. 1(1), 113, 114(2) (with reg. 138)
Pt. 1 modified (2.4.1999) by The New Deal (25 plus) (Miscellaneous Provisions) Order 1999 (S.I. 1999/779), arts. 1(1), 2
S. 1(2)(bb) inserted (8.9.1998 for specified purposes, 6.4.1999 in so far as not already in force) by Social Security Act 1998 (c. 14), s. 87(2), Sch. 7 para. 56(1); S.I. 1998/2209, art. 2(b)(c), Sch. Pts. 2, 3
Word in s. 1(4)(a) inserted (8.9.1998 for specified purposes, 6.4.1999 in so far as not already in force) by Social Security Act 1998 (c. 14), s. 87(2), Sch. 7 para. 56(2); S.I. 1998/2209, art. 2(b)(c), Sch. Pts. 2, 3
Pt. 1 modified (13.9.2001) by The New Deal (Lone Parents) (Miscellaneous Provisions) Order 2001 (S.I. 2001/2915), arts. 1(1), 2
Words in s. 1(5) substituted (8.12.2002) by Employment Act 2002 (c. 22), ss. 6(3), 55(2); S.I. 2002/2866, art. 2(2), Sch. 1 Pt. 2
Words in s. 1(2)(bb) substituted (6.4.2003 with effect in accordance with s. 723(1)(a)(b) of the amending Act) by Income Tax (Earnings and Pensions) Act 2003 (c. 1), s. 723, Sch. 6 para. 170 (with Sch. 7)
Words in s. 1(2)(d) inserted (6.4.2009) by Pensions Act 2008 (c. 30), ss. 135(3), 149(4)
Word in s. 1(2)(c) omitted (with effect for the tax year 2015-16 and subsequent tax years) by virtue of National Insurance Contributions Act 2015 (c. 5), Sch. 1 paras. 2, 35
Words in s. 1(5) substituted (5.4.2015) by Children and Families Act 2014 (c. 6), s. 139(6), Sch. 7 para. 7(a); S.I. 2014/1640, art. 7(d) (with art. 16)
Word in s. 1(2) omitted (12.10.2015) by virtue of Pensions Act 2014 (c. 19), s. 56(1), Sch. 15 para. 2(2)(a); S.I. 2015/1475, art. 3(b)
S. 1(2)(da) inserted (12.10.2015) by Pensions Act 2014 (c. 19), s. 56(1), Sch. 15 para. 2(2)(b); S.I. 2015/1475, art. 3(b)
Words in s. 1(4)(a) substituted (12.10.2015) by Pensions Act 2014 (c. 19), s. 56(1), Sch. 15 para. 2(3); S.I. 2015/1475, art. 3(b)
Words in s. 1(1)(a) inserted (6.4.2016) by Pensions Act 2014 (c. 19), s. 56(4), Sch. 12 para. 3
Words in s. 1(3) omitted (6.4.2016) by virtue of Pensions Act 2014 (c. 19), s. 56(4), Sch. 13 para. 49
Pt. 1 modified (6.4.2001) by The Social Security (Contributions) Regulations 2001 (S.I. 2001/1004), regs. 1(1), 125 (as amended (6.4.2017) by S.I. 2017/416, regs. 1(2), 2; (6.4.2019) by S.I. 2019/555, regs. 1(2), 2)
Words in s. 1(5) substituted (18.1.2020) by Parental Bereavement (Leave and Pay) Act 2018 (c. 24), s. 2(2), Sch. para. 10; S.I. 2020/45, reg. 2
Pt. 1 modified (for the tax year 2022-23) by Health and Social Care Levy Act 2021 (c. 28), s. 5(2) (with s. 7(2)) (which Act was repealed (25.10.2022) by Health and Social Care Levy (Repeal) Act 2022 (c. 43), s. 1 (with savings and transitional modifications of Pt. 1 in s. 2, Sch. paras. 1-3, 5))
Pt. 1 modified (in relation to the tax year 2023-24) by National Insurance Contributions (Reduction in Rates) Act 2023 (c. 57), Sch. para. 1(1)-(3)
S. 1(6)(aa) inserted (6.4.2024) by The Social Security (Class 2 National Insurance Contributions) (Consequential Amendments and Savings) Regulations 2024 (S.I. 2024/377), regs. 1(1), 5(1) (with reg. 1(4))
Words in s. 1(5) substituted (17.1.2025) by Neonatal Care (Leave and Pay) Act 2023 (c. 20), s. 3(3), Sch. para. 10; S.I. 2025/41, reg. 2