| # | Tower | No | Year | Materials | Maker | Trusses | Layout |
| 4601 | Inworth, Essex, All Saints | 1 | c1877 | Timber | | 6.A | 5.1 |
| 4602 | Iping, West Sussex, S Mary | 1 | | Oak | | 6.M | 1 |
| 4603 | Ipplepen, Devon, S Andrew | 1 | 1950 | Cast iron | Gillett & Johnston | 8.3.A.m | 8.3 |
| 4604 | Ipsley, Worcestershire, S Peter | 1 | 1971 | Cast iron | John Taylor & Co | | 6 |
| 4605 | Ipstones, Staffordshire, S Leonard | 1 | 2017 | Steel | Local labour/guild/assn | 8.1.B.c | 6.1 |
| 4606 | Ipswich, Suffolk, All Hallows | 1 | | Steel | | 8.1.A | |
| 4607 | Ipswich, Suffolk, S Clement | 2 | c1921 | Cast iron | Alfred Bowell | 8.3.A.h | 1 |
| 4608 | Ipswich, Suffolk, S Clement | 1 | c1921 | Steel | Alfred Bowell | 8.1.C.a | |
| 4609 | Ipswich, Suffolk, S Lawrence | 1 | 2009 | Steel | Whitechapel Bell Foundry | | 5.1 |
| 4610 | Ipswich, Suffolk, S Margaret | 2 | 1899 | Cast iron & oak | Alfred Bowell | 6.A | 8.1 |
| 4611 | Ipswich, Suffolk, S Margaret | 1 | 2018 | Steel | Nicholson Engineering Ltd | 8.1.B.a | 8.3 |
| 4612 | Ipswich, Suffolk, S Mary at the Elms | 1 | c1599 | Oak | | 5.H | 5.8 |
| 4613 | Ipswich, Suffolk, S Mary at the Quay | 1 | c1775 | Oak | | 10 | 6.7 |
| 4614 | Ipswich, Suffolk, Minster Ch of S Mary le Tower | 2 | 1976 | Cast iron | John Taylor & Co | 8.3.A.h | 4 |
| 4615 | Ipswich, Suffolk, Minster Ch of S Mary le Tower | 2.1 | 1999 | Steel | John Taylor & Co | | |
| 4616 | Ipswich, Suffolk, Minster Ch of S Mary le Tower | 2.2 | 1999 | Steel | John Taylor & Co | | |
| 4617 | Ipswich, Suffolk, Minster Ch of S Mary le Tower | 1 | 1976 | Cast iron | John Taylor & Co | 8.3.A.h | 9 |
| 4618 | Ipswich, Suffolk, S Matthew | 1 | 1903 | Oak | Alfred Bowell | 6.A | 6.4 |
| 4619 | Ipswich, Suffolk, S Nicholas | 1 | c1706 | Oak | | 5.D | 5.1 |
| 4620 | Ipswich, Suffolk, S Stephen | 1 | c1629 | Timber | | 10 | 3.1 |
| 4621 | Ipswich, Suffolk, S Thomas Ap | 1 | | Steel | | 8.1.E | 1 |
| 4622 | Irby in the Marsh, Lincolnshire, All Saints | 1 | 1717 | Timber | | | |
| 4623 | Irby upon Humber, Lincolnshire, S Andrew | 1 | | Timber | | 6.B | 3.3 D |
| 4624 | Irchester, Northamptonshire, S Katharine | 2 | 1930 | Cast iron | John Taylor & Co | | 4 |
| 4625 | Irchester, Northamptonshire, S Katharine | 1 | 1930 | Cast iron | John Taylor & Co | | 4 |
| 4626 | Irnham, Lincolnshire, S Andrew | 1 | | Cast iron | John Taylor & Co | | |
| 4627 | Iron Acton, Gloucestershire, S James Less | 1 | 1884 | Timber | John Taylor & Co | 6.A | 6.4 |
| 4628 | Irthlingborough, Northamptonshire, S Peter | 1 | 1893 | Cast iron | John Taylor & Co | 8.3.C.e | 8.3 |
| 4629 | Isham, Northamptonshire, S Peter | 1 | 1906 | Metal | John Taylor & Co | | |
| 4630 | Isle Abbotts, Somerset, Blessed Virgin Mary | 2 | c1600 | Oak | | | |
| 4631 | Isle Abbotts, Somerset, Blessed Virgin Mary | 1 | 1999 | Steel | Eayre & Smith | | |
| 4632 | Isle Brewers, Somerset, All Saints | 1 | c1859 | Oak | | | |
| 4633 | Isle of Dogs, Greater London, Christ Church | 1 | 1907 | Cast iron | Mears & Stainbank | | |
| 4634 | Isle of Sark, Sark, Channel Islands, S Peter | 1 | c1883 | Softwood | | 6 | |
| 4635 | Isleham, Cambridgeshire, S Andrew | 9 | | | | | |
| 4636 | Isleham, Cambridgeshire, S Andrew | 1 | 1969 | Cast iron | John Taylor & Co | 8.3.A.h | 6.1 |
| 4637 | Isleworth, Greater London, All Saints | 8 | | | | | |
| 4638 | Isleworth, Greater London, All Saints | 2 | 1931 | Metal | Mears & Stainbank | | |
| 4639 | Isleworth, Greater London, All Saints | 1 | 1903 | Cast iron | John Taylor & Co | 8.3.C.e | |
| 4640 | Islington, Greater London, S James Ap | 1 | 1875 | Oak | ? John Warner & Sons | 6.A | 6.4 |
| 4641 | Islington, Greater London, S Mary V | 1 | 2002 | Cast iron | Hayward Mills Associates | 8.3.A.h | 8.3 D |
| 4642 | Islip, Northamptonshire, S Nicholas | 1 | 1892 | Cast iron & oak | John Taylor & Co | | 6 |
| 4643 | Itchen Stoke, Hampshire, S Mary V | 1 | | Stone | | 9.A | 1 |
| 4644 | Itchingfield, West Sussex, S Nicolas | 1 | 1866 | Timber | | 6.A | 5.1 |
| 4645 | Iver, Buckinghamshire, S Peter | 1 | 1938 | Steel | Gillett & Johnston | 8.1.B.d | 8.3 |
| 4646 | Ivinghoe, Buckinghamshire, S Mary V | 1 | c1715 | Timber | | 6.A & 6.H | |
| 4647 | Ivychurch, Kent, S George | 1 | c1599 | Timber | | | 5.X |
| 4648 | Iwerne Courtney, Dorset, S Mary | 1 | 1908 | Wrought steel | Mears & Stainbank | 8.1.B.a | 6.5 R |
| 4649 | Iwerne Minster, Dorset, S Mary | 2 | 1979 | Steel | Whitechapel Bell Foundry | | |
| 4650 | Iwerne Minster, Dorset, S Mary | 1 | 1979 | Cast iron & steel | Whitechapel Bell Foundry | 8.3.A | 5.1 |