EVENT 505 Open/Male 400m IM - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 3 | 1 | Maxwell Millington | 15 | Nova Cent'n | 5:14.87 |
| 4 | 3 | Thomas Collins | 14 | Bassetlaw SS | 5:14.40 |
| 5 | 2 | William Newham | 15 | Calv Bing | 5:14.43 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 5 | Jake Battle | 13 | Repton | 5:14.15 |
| 2 | 7 | Jack Hicks | 15 | Lincoln Vulc | 5:13.43 |
| 3 | 9 | Ethan Simmonds | 15 | Co Leicester | 5:11.64 |
| 4 | 11 | Samuel Green | 14 | Bassetlaw SS | 5:10.80 |
| 5 | 10 | Emerson-Blu Gupwell | 14 | Co Leicester | 5:11.08 |
| 6 | 8 | Freddie Burdett | 14 | Co Leicester | 5:12.20 |
| 7 | 6 | Oliver Lond | 16 | Hinckley | 5:13.61 |
| 8 | 4 | Maxwell Burdett | 12 | Co Leicester | 5:14.39 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 13 | Lucas Kimber | 15 | Derby Excel | 5:09.80 |
| 2 | 15 | Brodie Butlin | 15 | Nova Cent'n | 5:08.63 |
| 3 | 17 | Jacson Crabb | 13 | Co Leicester | 5:08.48 |
| 4 | 19 | Benjamin Derby | 16 | Lincoln Vulc | 5:06.01 |
| 5 | 18 | Eddie Baron | 15 | Nova Cent'n | 5:06.82 |
| 6 | 16 | Harry Lucas | 14 | Co Leicester | 5:08.60 |
| 7 | 14 | Zachary Jones | 15 | Northampton | 5:09.30 |
| 8 | 12 | Edward Oscroft | 15 | Northampton | 5:10.23 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 21 | Lawrence Chapman | 16 | Worksop | 5:03.05 |
| 2 | 23 | William Oxley | 14 | Co Leicester | 5:00.30 |
| 3 | 25 | Jack Goldfinch | 18 | Loughborough | 4:53.26 |
| 4 | 27 | Thomas Townsend | 15 | Repton | 4:50.70 |
| 5 | 26 | Jacob Fish | 15 | Grantham | 4:51.84 |
| 6 | 24 | Edun Rowe | 16 | Northampton | 4:59.10 |
| 7 | 22 | Joel Harby | 15 | Nova Cent'n | 5:02.57 |
| 8 | 20 | Oliver Smith | 15 | Radford | 5:05.43 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 29 | Jack Hurry | 15 | Northampton | 4:49.10 |
| 2 | 31 | Niklas Saukko-Paavola | 16 | Nova Cent'n | 4:47.40 |
| 3 | 33 | Noah Van Hoorebeek | 17 | Chesterfield | 4:43.60 |
| 4 | 35 | Findlay Cordle | 17 | Repton | 4:37.63 |
| 5 | 34 | James Lake | 17 | Loughborough | 4:41.51 |
| 6 | 32 | Austyn Manley | 14 | Repton | 4:46.33 |
| 7 | 30 | Luke Chambers | 16 | Derby Excel | 4:48.55 |
| 8 | 28 | Jack Smith | 14 | Co Leicester | 4:50.60 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 37 | Joseph Mulligan | 18 | Nova Cent'n | 4:34.95 |
| 2 | 39 | Oliver Caddick | 19 | Lboro Uni | 4:34.35 |
| 3 | 41 | Thomas Wilkinson | 18 | Lboro Uni | 4:23.43 |
| 4 | 43 | Max Litchfield | 29 | Lboro Uni | 4:01.70 |
| 5 | 42 | Vadim Bosc | 19 | Lboro Uni | 4:18.08 |
| 6 | 40 | Luke Ibbeson | 21 | Lboro Uni | 4:30.30 |
| 7 | 38 | Elliot Sibley | 19 | Nova Cent'n | 4:34.88 |
| 8 | 36 | Jack Bignell | 16 | Northampton | 4:37.60 |