EVENT 402 Female 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 4 | Surina CHAUHAN-FRANCE | 13 | Dunstable | |
| 3 | 6 | Summer ZHANG | 12 | Ealing | |
| 4 | 8 | Kylie VOSLOO | 12 | Wycombe Dist | |
| 5 | 7 | Lottie BASSINGTON | 12 | Bletchley | |
| 6 | 5 | Zuzanna WALASZEK | 12 | Team Luton | |
| 7 | 2 | Olivia FOUFA | 11 | Wycombe Dist | |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 10 | Carla GARCIA-RONCERO | 11 | Ealing | |
| 2 | 12 | Ella WEDD | 11 | Wycombe Dist | |
| 3 | 14 | Bethany RUSTON | 11 | Team Luton | |
| 4 | 17 | Anastasia OLSZEWSKA | 11 | Co Milton K | |
| 5 | 16 | Isabella GEARY | 14 | Dunstable | |
| 6 | 13 | Sophie LAPUCHA | 12 | Team Luton | |
| 7 | 11 | Sara BOUKHTOUCHE | 10 | Ealing | |
| 8 | 9 | Eloisa SMET | 15 | Wycombe Dist | |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 19 | Vlada HAVRYLIUK | 16 | Team Luton | |
| 2 | 21 | Esther SPENCER | 11 | Biggleswade | |
| 3 | 23 | Charlotte TAPE | 10 | Bo Southend | 6:51.19 |
| 4 | 25 | Emilia POTTER | 11 | Wycombe Dist | 6:40.10 |
| 5 | 24 | Sara WAGAN | 10 | Putteridge | 6:50.12 |
| 6 | 22 | Mia HARPER | 12 | Biggleswade | 7:04.57 |
| 7 | 20 | Yuika NAGANUMA | 10 | Ealing | |
| 8 | 18 | Emma NOON | 11 | Dunstable | |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 28 | Inika SHARMA | 13 | Co Milton K | 6:11.25 |
| 2 | 30 | Amelia JN BAPTISTE | 10 | Bark & Dagen | 6:05.00 |
| 3 | 32 | Katherine SINKER | 12 | Ealing | 6:01.82 |
| 4 | 34 | Leyla FORBES | 11 | Co Milton K | 5:56.41 |
| 5 | 33 | Allegra CARBONE | 11 | Ealing | 5:57.55 |
| 6 | 31 | Leonie TALARCZYK-BROWN | 11 | Wycombe Dist | 6:04.30 |
| 7 | 29 | Hannah MILLS | 14 | Wycombe Dist | 6:07.70 |
| 8 | 26 | Grace FAHEY | 10 | Berkhamsted | 6:23.14 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 66 | Ella BOYADJIAN | 14 | Wycombe Dist | 5:55.50 |
| 2 | 67 | Madeleine ARMSTRONG | 12 | Wycombe Dist | 5:50.55 |
| 3 | 38 | Saanvi KAWLE | 14 | Co Milton K | 5:43.84 |
| 4 | 68 | Lexie WARWICK | 12 | Wycombe Dist | 5:43.17 |
| 5 | 39 | Stephanie GUSTHOFF | 10 | Co Milton K | 5:43.63 |
| 6 | 37 | Carolina PRUSAK | 13 | Team Luton | 5:48.14 |
| 7 | 35 | Gina COLLINSON | 14 | Verulam | 5:55.38 |
| 8 | 65 | Isabelle AKINBADE | 10 | Wycombe Dist | 5:55.57 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 41 | Emily TAPE | 12 | Bo Southend | 5:38.43 |
| 2 | 71 | Annabel HEWITT | 12 | Wycombe Dist | 5:36.50 |
| 3 | 43 | Annabella SCOTT | 12 | Ealing | 5:35.70 |
| 4 | 72 | Theadora STOPP | 12 | Wycombe Dist | 5:34.30 |
| 5 | 44 | Amy CLARKE | 13 | TigersJersey | 5:34.99 |
| 6 | 42 | Keira Rose BOUQUET | 12 | Ealing | 5:36.40 |
| 7 | 70 | Charlotte FITZHERBERT | 12 | Wycombe Dist | 5:38.26 |
| 8 | 40 | Erin SMITH | 11 | Berkhamsted | 5:41.02 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 48 | Thea SLATER | 14 | Team Luton | 5:28.84 |
| 2 | 51 | Gabrielle GAO | 13 | Ealing | 5:27.05 |
| 3 | 53 | Isla MCDONNELL | 17 | Harpenden | 5:24.08 |
| 4 | 56 | Nicole CALIN | 12 | Ealing | 5:21.30 |
| 5 | 55 | Sophie BARRY | 14 | Bo Southend | 5:21.87 |
| 6 | 52 | Madison BROWN | 16 | Bletchley | 5:25.74 |
| 7 | 49 | Darcy DEAR | 15 | Dunstable | 5:28.37 |
| 8 | 47 | Abbie WHITE | 12 | Biggleswade | 5:30.00 |
| Heat Number - 8 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 57 | Inaaya SAMPONG | 13 | Team Luton | 5:16.04 |
| 2 | 59 | Annabelle SAINS | 13 | Co Milton K | 5:03.69 |
| 3 | 61 | Anna INGRAM | 15 | Ealing | 5:00.60 |
| 4 | 63 | Victoria GRANT | 12 | TigersJersey | 4:54.10 |
| 5 | 62 | Emily JOYCE | 13 | Biggleswade | 4:58.70 |
| 6 | 60 | Mia ECKLEY | 12 | Co Milton K | 5:02.02 |
| 7 | 58 | Olivia RING | 13 | Co Milton K | 5:05.94 |
| 8 | 73 | Martha CORMIE | 10 | Wycombe Dist | 5:19.10 |