| Tax Credits Act 1999 | 1999 c. 10 | Act | repealed | Tax Credits Act 2002 | 2002 c. 21 | Sch. 6 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Act | savings for effects of SI 2003/962 | Commissioners for Revenue and Customs Act 2005 | 2005 c. 11 | Sch. 4 para. 92 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | s. 5(2) | | Government Resources and Accounts Act 2000 | 2000 c. 20 | Sch. 1 para. 25 | Yes | |
| Tax Credits Act 1999 (repealed) | 1999 c. 10 | s. 6(1) | words substituted | Income Tax (Earnings and Pensions) Act 2003 | 2003 c. 1 | Sch. 6 para. 240 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | s. 15 | | not available | 2000 No. 253 | art. 2 | Yes | |
| Tax Credits Act 1999 (repealed) | 1999 c. 10 | s. 15 | | The Scotland Act 1998 (Transfer of Functions to the Scottish Ministers etc.) Order 2000 | 2000 No. 1563 | art. 5(2) | Yes | |
| Tax Credits Act 1999 (repealed) | 1999 c. 10 | s. 15(3) | | The Scotland Act 1998 (Transfer of Functions to the Scottish Ministers etc.) Order 2000 | 2000 No. 1563 | sch. | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | s. 18 | words inserted | Employment Act 2002 | 2002 c. 22 | Sch. 7 para. 52 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 1 para. 2 | repealed in part | Welfare Reform and Pensions Act 1999 | 1999 c. 30 | Sch. 13 Pt. 4 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 1 para. 4 | repealed in part (NI) (prosp.) | The Welfare Reform and Pensions (Northern Ireland) Order 1999 | 1999 No. 3147 | Sch. 10 Pt. 4 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 1 para. 6(l) | repealed | Child Support, Pensions and Social Security Act (Northern Ireland) | 2000 c. 4 | Sch. 9 Pt. 1 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 1 para. 6(i) | repealed | Child Support, Pensions and Social Security Act 2000 | 2000 c. 19 | Sch. 9 Pt. 1 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 1 para. 2(d) | | The Welfare Reform and Pensions Act 1999 (Commencement No. 9, and Transitional and Savings Provisions) Order 2000 | 2000 No. 2958 | art. 2(3)(g)(5) | Yes | |
| Tax Credits Act 1999 (repealed) | 1999 c. 10 | Sch. 1 para. 6(c) | repealed | Income Tax (Earnings and Pensions) Act 2003 | 2003 c. 1 | Sch. 8 Pt. 1 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 1 para. 6(a) | repealed | Courts Act 2003 | 2003 c. 39 | Sch. 10 | See note | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 2 para. 24 | repealed (6.4.2000) | Welfare Reform and Pensions Act 1999 | 1999 c. 30 | Sch. 13 Pt. 7 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 2 para. 11(b) | repealed | Child Support, Pensions and Social Security Act (Northern Ireland) | 2000 c. 4 | Sch. 9 Pt. 5 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 2 para. 13(b) | repealed | Child Support, Pensions and Social Security Act (Northern Ireland) | 2000 c. 4 | Sch. 9 Pt. 5 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 2 para. 14(b) | repealed | Child Support, Pensions and Social Security Act (Northern Ireland) | 2000 c. 4 | Sch. 9 Pt. 5 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 2 para. 17(b) | repealed | Child Support, Pensions and Social Security Act (Northern Ireland) | 2000 c. 4 | Sch. 9 Pt. 1 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 2 para. 11(a) | repealed | Child Support, Pensions and Social Security Act 2000 | 2000 c. 19 | Sch. 9 Pt. 6 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 2 para. 13(a) | repealed | Child Support, Pensions and Social Security Act 2000 | 2000 c. 19 | Sch. 9 Pt. 6 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 2 para. 14(a) | repealed | Child Support, Pensions and Social Security Act 2000 | 2000 c. 19 | Sch. 9 Pt. 6 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 2 para. 17(a) | repealed | Child Support, Pensions and Social Security Act 2000 | 2000 c. 19 | Sch. 9 Pt. 1 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 2 para. 24 | words substituted | The Secretaries of State for Education and Skills and for Work and Pensions Order 2002 | 2002 No. 1397 | Sch. para. 15 | Yes | |
| Tax Credits Act 1999 (repealed) | 1999 c. 10 | Sch. 2 para. 10(1) | words substituted | Income Tax (Earnings and Pensions) Act 2003 | 2003 c. 1 | Sch. 6 para. 241 | Yes | |
| Tax Credits Act 1999 (repealed) | 1999 c. 10 | Sch. 3 para. 1 | amended | Employment Relations Act 1999 | 1999 c. 26 | s. 18(5) | Yes | |
| Tax Credits Act 1999 (repealed) | 1999 c. 10 | Sch. 3 para. 1(3) | words repealed | The Employment Relations (Northern Ireland) Order 1999 | 1999 No. 2790 | art. 20(5)(b) Sch. 9(3) | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 5 para. 2(2) | words inserted | Employment Act 2002 | 2002 c. 22 | Sch. 6 para. 9(a)(i) | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 5 para. 2(2) | words inserted | Employment Act 2002 | 2002 c. 22 | Sch. 6 para. 9(a)(ii) | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 5 para. 2(2A) | inserted | Employment Act 2002 | 2002 c. 22 | Sch. 6 para. 9(b) | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 5 para. 2(3) | words substituted | Employment Act 2002 | 2002 c. 22 | Sch. 6 para. 9(c) | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 5 para. 3(1) | words inserted | Employment Act 2002 | 2002 c. 22 | Sch. 6 para. 10(a) | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 5 para. 3(2) | words inserted | Employment Act 2002 | 2002 c. 22 | Sch. 6 para. 10(b) | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 5 para. 3(2A) | inserted | Employment Act 2002 | 2002 c. 22 | Sch. 6 para. 10(c) | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | Sch. 6 | repealed in part (6.4.2000) | Welfare Reform and Pensions Act 1999 | 1999 c. 30 | Sch. 13 Pt. 7 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | | Commencement Order | Employment Relations (1999 Order) (Commencement No. 1 and Transitional and Saving Provisions) Order (Northern Ireland) 1999 | 1999 No. 470 | | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | | Commencement Order | The Employment Relations Act 1999 (Commencement No. 2 and Transitional and Saving Provisions) Order 1999 | 1999 No. 2830 | | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | | Commencement Order | The Welfare Reform and Pensions Act 1999 (Commencement No. 2) Order 1999 | 1999 No. 3420 | | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | C/O | Commencement Order | The Welfare Reform and Pensions (1999 Order) (Commencement No. 6 and Transitional and Savings Provisions) Order (Northern Ireland) 2000 | 2000 No. 332 | s. 40 Sch. 2 Pt. 2 para. 4068 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | C/O | Commencement Order | The Welfare Reform and Pensions Act 1999 (Commencement No. 9, and Transitional and Savings Provisions) Order 2000 | 2000 No. 2958 | art. 2(3)(g) | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | C/O | Commencement Order | The Government Resources and Accounts Act 2000 (Commencement No. 1 and Transitional Provision) Order 2000 | 2000 No. 3349 | arts. 2 - 4 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | C/O | Commencement Order | The Child Support, Pensions and Social Security (2000 Act) (Commencement No. 5) Order (Northern Ireland) 2001 | 2001 No. 141 | art. 2(1) | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | c/o | Commencement Order | The Child Support, Pensions and Social Security Act 2000 (Commencement No. 8) Order 2001 | 2001 No. 1252 | art. 2 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | specified amended provision(s) | Commencement Order | The Tax Credits Act 2002 (Commencement No. 1) Order 2002 | 2002 No. 1727 | art. 2 | Yes |   commencement order for 2002 c. 21. This SI is amended by SI 2002/2158 |
| Tax Credits Act 1999 | 1999 c. 10 | specified amended provision(s) | Commencement Order | The Employment Act 2002 (Commencement No. 2) Order 2002 | 2002 No. 2256 | art. 2 | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | specified amended provision(s) | Commencement Order | The Employment Act 2002 (Commencement No. 3 and Transitional and Saving Provisions) Order 2002 | 2002 No. 2866 | art. 2 Sch. | Yes | |
| Tax Credits Act 1999 | 1999 c. 10 | specified amended provision(s) | Commencement Order | The Child Support, Pensions and Social Security (2000 Act) (Commencement No. 9) Order (Northern Ireland) 2003 | 2003 No. 53 | art. 2-7 Sch. | Yes |   commencement order for 2000 c. 4 (N.I.) |
| Tax Credits Act 1999 | 1999 c. 10 | specified amended provision(s) | Commencement Order | The Child Support, Pensions and Social Security Act 2000 (Commencement No. 12) Order 2003 | 2003 No. 192 | art. 3 6 Sch. | Yes |   commencement order for 2000 c. 19 |
| Tax Credits Act 1999 | 1999 c. 10 | specified amended provision(s) | Commencement Order | The Tax Credits Act 2002 (Commencement No. 4, Transitional Provisions and Savings) Order 2003 | 2003 No. 962 | art. 2 Sch. 1 2 | Yes |   commencement order for 2002 c. 21 |