EVENT 204 Mixed 800m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 3 | 1 | Ned Peter ANDREWS | 12 | Haringey | |
| 4 | 3 | Fia BURR | 13 | Biggleswade | |
| 5 | 2 | Ella PRUCE | 13 | Team Luton | |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 5 | Max HART | 10 | Verulam | |
| 2 | 7 | Edward BEARD | 13 | Verulam | |
| 3 | 9 | Ines PUENTE | 12 | Haringey | |
| 4 | 12 | Libby FLITTON | 11 | Dunstable | |
| 5 | 10 | David DOCHITOIU BARAU | 13 | Haringey | |
| 6 | 8 | Henry CHALONER | 12 | Biggleswade | |
| 7 | 6 | Thomas FENWICK | 13 | Team Luton | |
| 8 | 4 | Chloe MATTHEWS | 12 | Linslade | |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 14 | Joshua BEARD | 11 | Verulam | |
| 2 | 16 | An Clementine SO | 15 | Verulam | |
| 3 | 18 | Rannie JONES | 13 | Haringey | |
| 4 | 21 | Elissa NEO | 11 | Linslade | |
| 5 | 19 | Lauren CALVERT | 15 | Team Luton | |
| 6 | 17 | Benjamin MELLORS | 13 | Verulam | |
| 7 | 15 | Albert NEZHA | 12 | Haringey | |
| 8 | 13 | Evie ARMSTRONG | 11 | Dunstable | |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 23 | Gina COLLINSON | 12 | Team Luton | |
| 2 | 25 | Connie FLITTON | 13 | Dunstable | |
| 3 | 27 | Amy MEYER | 14 | Biggleswade | |
| 4 | 28 | Harrison COPE | 11 | TigersJersey | 13:34.50 |
| 5 | 65 | Selina GREEN | 14 | New Hall | 16:00.00 |
| 6 | 26 | Lauren IBBOTSON | 10 | Linslade | |
| 7 | 24 | Callum RICHARDS | 13 | Harpenden | |
| 8 | 22 | Kevin NEZHA | 18 | Haringey | |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 31 | Elizabeth STOCKS | 11 | Linslade | 12:29.29 |
| 2 | 33 | Aaron RAWNSLEY | 12 | Harpenden | 12:20.40 |
| 3 | 35 | Cerys LONG | 12 | Linslade | 12:08.47 |
| 4 | 38 | Tara SHAH | 13 | Bushey | 11:50.80 |
| 5 | 37 | Coral TURNER | 13 | Biggleswade | 11:57.60 |
| 6 | 34 | Clara LEON | 12 | Team Luton | 12:09.00 |
| 7 | 32 | Victoria GRANT | 10 | TigersJersey | 12:22.10 |
| 8 | 29 | Alex O'NEIL | 13 | Verulam | 13:15.30 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 40 | Lucia DAY | 12 | Team Luton | 11:28.87 |
| 2 | 43 | Eliza JENNINGS | 12 | Biggleswade | 11:12.80 |
| 3 | 45 | Jack CANHAM | 12 | Team Luton | 11:09.22 |
| 4 | 47 | Joseph FINNERTY | 16 | Linslade | 11:01.40 |
| 5 | 46 | Imogen FORRESTER | 14 | Deben | 11:05.77 |
| 6 | 44 | Angelica LAZAUSKAITE | 16 | Watford SC | 11:09.30 |
| 7 | 42 | Elizabeth STEVENSON | 15 | Biggleswade | 11:21.70 |
| 8 | 39 | Emily CALVERT | 13 | Team Luton | 11:30.70 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 49 | Emilie HIGGS | 14 | Newport Pag | 10:54.70 |
| 2 | 52 | Zente BUZSIK | 13 | Haringey | 10:33.79 |
| 3 | 54 | Xavier ZERBAN | 13 | Biggleswade | 10:16.24 |
| 4 | 56 | Evie WOOD | 22 | Braunstone | 10:12.90 |
| 5 | 55 | Alexander GAYDON | 13 | Colchester | 10:14.93 |
| 6 | 53 | Owain ROBERTS | 15 | Team Luton | 10:26.20 |
| 7 | 51 | Heather ELRICK | 15 | Newport Pag | 10:45.21 |
| 8 | 48 | Niamh CHURCH | 12 | TigersJersey | 10:55.22 |
| Heat Number - 8 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 58 | William HARRIS | 15 | Watford SC | 9:54.40 |
| 2 | 60 | Eveline GAYDON | 15 | Colchester | 9:53.14 |
| 3 | 62 | Charlie CUNNINGHAM | 14 | Biggleswade | 9:51.37 |
| 4 | 64 | Oliver FENWICK | 15 | Team Luton | 9:36.35 |
| 5 | 63 | Daniel DICK | 16 | Newport Pag | 9:39.20 |
| 6 | 61 | Ewan LONG | 15 | Linslade | 9:52.40 |
| 7 | 59 | ORLAGH QUARRELL | 13 | Broomfield | 9:53.48 |
| 8 | 57 | Arthur COLDWELL | 17 | Watford SC | 9:57.80 |