EVENT 102 Female 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 1 | Emily BRATILESCU | 11 | Newport Pag | |
| 2 | 3 | Tilly SCRIVENER | 11 | Team Luton | |
| 3 | 5 | Gina COLLINSON | 13 | Team Luton | |
| 4 | 7 | C YIP | 13 | Verulam | |
| 5 | 6 | Martha ROBINSON | 11 | Amersham | |
| 6 | 4 | Sunayana NANDA | 11 | Amersham | |
| 7 | 2 | Eleana EDWARDS | 13 | Newport Pag | |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 9 | Cora PAYNE | 10 | Dunstable | 6:14.97 |
| 2 | 11 | Inika SHARMA | 12 | Co Milton K | 6:11.25 |
| 3 | 14 | Annabelle SAINS | 11 | Co Milton K | 6:03.14 |
| 4 | 16 | Mia ECKLEY | 10 | Co Milton K | 5:58.93 |
| 5 | 15 | Saanvi KAWLE | 12 | Co Milton K | 6:00.44 |
| 6 | 12 | Inaaya SAMPONG | 11 | Team Luton | 6:06.80 |
| 7 | 10 | Ruth BISCOE | 10 | Team Luton | 6:12.60 |
| 8 | 8 | Thea SLATER | 12 | Team Luton | |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 18 | Kira BELYAKOVA | 14 | Camden Swiss | 5:54.37 |
| 2 | 21 | Amelia SINCLAIR | 14 | Camden Swiss | 5:52.34 |
| 3 | 23 | Darcie CADER | 12 | Berkhamsted | 5:49.99 |
| 4 | 25 | G CROZIER-LITTLE | 13 | Dunstable | 5:44.83 |
| 5 | 24 | Matilda TOMKINSON | 11 | Co Milton K | 5:49.02 |
| 6 | 22 | Amélie DESMEULES | 10 | Verulam | 5:51.70 |
| 7 | 20 | Jaclyn LIAW | 13 | Camden Swiss | 5:52.54 |
| 8 | 17 | Billie-Paige KAVANAGH | 11 | Co Milton K | 5:57.29 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 27 | Ayla THIEDE | 12 | Camden Swiss | 5:39.58 |
| 2 | 29 | Talya BRONFENTRINKER | 13 | Camden Swiss | 5:37.17 |
| 3 | 31 | Kaylyn SAMPONG | 13 | Team Luton | 5:29.50 |
| 4 | 33 | Libby FLITTON | 11 | Dunstable | 5:26.80 |
| 5 | 32 | Olivia COOPER | 15 | Dunstable | 5:28.50 |
| 6 | 30 | Giulia LEFEVRE | 14 | Camden Swiss | 5:35.49 |
| 7 | 28 | Bethany QUINN | 15 | Co Milton K | 5:38.01 |
| 8 | 26 | Zara CHAMORRO | 15 | Camden Swiss | 5:39.80 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 35 | Siobhan SCHNEIDER | 14 | Bedford SS | 5:24.10 |
| 2 | 37 | Analise COMER | 14 | Camden Swiss | 5:22.02 |
| 3 | 40 | Isla MOHAMMED | 14 | Aylesbury | 5:16.78 |
| 4 | 43 | Alice BUCKINGHAM | 11 | Team Luton | 5:15.10 |
| 5 | 42 | Ashley-Jane ANG | 12 | Camden Swiss | 5:16.50 |
| 6 | 39 | Amelia DONNELLY | 12 | Camden Swiss | 5:18.03 |
| 7 | 36 | Charlotte BARNARD | 13 | Camden Swiss | 5:23.50 |
| 8 | 34 | Tess JACKSON | 15 | Camden Swiss | 5:26.00 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 46 | Sophia GUSTHOFF | 15 | Co Milton K | 5:13.84 |
| 2 | 48 | Annabella COJEEN | 13 | Aylesbury | 5:12.07 |
| 3 | 50 | Eva CHAMORRO | 13 | Camden Swiss | 5:06.76 |
| 4 | 52 | Eva-May BOWIE | 13 | Bedford SS | 5:05.80 |
| 5 | 51 | Connie FLITTON | 13 | Dunstable | 5:05.90 |
| 6 | 49 | Lana WAHLBERG | 13 | Amersham | 5:10.80 |
| 7 | 47 | Marina FANARI-GIBBONS | 14 | Camden Swiss | 5:13.75 |
| 8 | 45 | Juliette LEMAITRE | 16 | Camden Swiss | 5:13.88 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 55 | Charlotte BELCHER | 14 | Bedford SS | 5:03.60 |
| 2 | 58 | Heather ELRICK | 15 | Newport Pag | 4:59.80 |
| 3 | 60 | Maya AL FAISAL | 15 | Camden Swiss | 4:58.12 |
| 4 | 62 | Jemima DA SILVA | 13 | Camden Swiss | 4:56.12 |
| 5 | 61 | Poppy MORRIS | 13 | Co Milton K | 4:56.64 |
| 6 | 59 | Isla PIPER | 13 | Co Milton K | 4:58.71 |
| 7 | 56 | Tia SAMMUT | 13 | Bedford SS | 5:03.40 |
| 8 | 54 | Aimee SANDERS | 12 | Dunstable | 5:04.94 |
| Heat Number - 8 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 64 | Elliana ZOBEL | 14 | Camden Swiss | 4:48.00 |
| 2 | 66 | Lydia SLADE-CARTER | 15 | Co Milton K | 4:45.27 |
| 3 | 70 | Eleanor PORTER | 13 | Camden Swiss | 4:41.20 |
| 4 | 72 | Lucia LOPEZ | 17 | Co Milton K | 4:26.40 |
| 5 | 71 | Jessica MEDLICOTT | 17 | Dunstable | 4:34.90 |
| 6 | 69 | Ava BENCH | 13 | Co Milton K | 4:41.50 |
| 7 | 65 | Nina MORII | 13 | Camden Swiss | 4:47.00 |
| 8 | 63 | Keira OSORIO | 15 | Camden Swiss | 4:53.96 |