| Heat Number - 1 | ||||||
| Lane | Comp.No. | Name | YoB | Cat | Club | Time |
| 1 | 2 | Charlotte BROWNLESS | 12 | Lincoln Trident Swimming Academy | 1:24.09 | |
| 2 | 4 | Eleanor BIRINY | 11 | Lincoln Vulcans SC | 1:14.27 | |
| 3 | 6 | Ava MALLOWS | 12 | Louth Dolphins SC | 1:18.66 | |
| 4 | 8 | Erin ARCHER | 11 | City of Linc Pentaqua SC | 1:16.29 | |
| 5 | 7 | Sophie FOSTER | 11 | Louth Dolphins SC | 1:18.85 | |
| 6 | 5 | Amelia BIRD | 11 | Skegness ASC | 1:13.47 | |
| 7 | 3 | Georgia MIDDLETON | 12 | Louth Dolphins SC | 1:24.28 | |
| 8 | 1 | Orlaigh GREER | 11 | S10 | South Lincs Competitive SC | 1:29.17 |
| Heat Number - 2 | ||||||
| Lane | Comp.No. | Name | YoB | Cat | Club | Time |
| 1 | 10 | Karolina PARKINSON | 10 | Lincoln Vulcans SC | 1:12.12 | |
| 2 | 12 | Suzanna BURKE | 11 | Louth Dolphins SC | 1:14.14 | |
| 3 | 14 | Maddison HODGIN | 10 | City of Linc Pentaqua SC | 1:11.30 | |
| 4 | 16 | Emilie WEBB | 10 | Grantham SC | 1:11.10 | |
| 5 | 15 | Emily TALKES | 12 | Lincoln Vulcans SC | 1:08.88 | |
| 6 | 13 | Megan RUTT | 10 | Boston Amateur SC | 1:13.33 | |
| 7 | 11 | Isobel ALLSOP | 10 | Grantham SC | 1:12.50 | |
| 8 | 9 | Amy BLOW | 11 | City of Linc Pentaqua SC | 1:14.29 | |
| Heat Number - 3 | ||||||
| Lane | Comp.No. | Name | YoB | Cat | Club | Time |
| 1 | 18 | Maisie MATTHEWS | 11 | Louth Dolphins SC | 1:10.12 | |
| 2 | 20 | Elysia SMITH | 10 | Louth Dolphins SC | 1:07.67 | |
| 3 | 22 | Amy PALMER | 11 | City of Linc Pentaqua SC | 1:07.61 | |
| 4 | 24 | Isabella MIDDLETON | 08 | Louth Dolphins SC | 1:12.33 | |
| 5 | 23 | Jessica - Rose DAVISON | 09 | Grantham SC | 1:07.38 | |
| 6 | 21 | Megan LAMB | 09 | Lincoln Vulcans SC | 1:07.43 | |
| 7 | 19 | Skye HOLMES | 10 | Louth Dolphins SC | 1:08.73 | |
| 8 | 17 | Isla GRAY | 10 | Grantham SC | 1:08.63 | |
| Heat Number - 4 | ||||||
| Lane | Comp.No. | Name | YoB | Cat | Club | Time |
| 1 | 26 | Sigourney BOLTON | 09 | South Lincs Competitive SC | 1:08.68 | |
| 2 | 28 | Isabelle MCCORKELL | 08 | Gainsborough Dolphins SC | 1:06.86 | |
| 3 | 30 | Kitty LAMB | 11 | South Lincs Competitive SC | 1:07.84 | |
| 4 | 32 | Rosie HICKS | 06 | Lincoln Vulcans SC | 1:08.91 | |
| 5 | 31 | Helena FIELD | 09 | Louth Dolphins SC | 1:06.74 | |
| 6 | 29 | Lucy WILSON | 10 | South Lincs Competitive SC | 1:09.47 | |
| 7 | 27 | Rianna ABBOTT | 08 | Grantham SC | 1:09.57 | |
| 8 | 25 | Elodie HILES | 08 | Louth Dolphins SC | 1:09.62 | |
| Heat Number - 5 | ||||||
| Lane | Comp.No. | Name | YoB | Cat | Club | Time |
| 1 | 34 | Olivia SPENCER | 06 | Lincoln Vulcans SC | 1:09.18 | |
| 2 | 36 | Emmy STINTON | 09 | City of Linc Pentaqua SC | 1:06.17 | |
| 3 | 38 | Sophie COOKSEY | 10 | Louth Dolphins SC | 1:10.04 | |
| 4 | 40 | Madeleine MACKAY | 98 | Lincoln Vulcans SC | 1:06.92 | |
| 5 | 39 | Gracie-May COLE | 08 | City of Linc Pentaqua SC | 1:07.52 | |
| 6 | 37 | Grace TWILTON | 08 | Lincoln Vulcans SC | 1:06.04 | |
| 7 | 35 | Florrie HENSMAN | 09 | Louth Dolphins SC | 1:08.55 | |
| 8 | 33 | Grace PECK | 07 | Louth Dolphins SC | 1:07.93 | |
| Heat Number - 6 | ||||||
| Lane | Comp.No. | Name | YoB | Cat | Club | Time |
| 1 | 42 | Taliah COUTTS | 08 | City of Linc Pentaqua SC | 1:05.65 | |
| 2 | 44 | Holly GILES | 06 | Louth Dolphins SC | 1:06.46 | |
| 3 | 46 | Alexandra HALLAM-STOTT | 06 | Grantham SC | 1:06.79 | |
| 4 | 48 | Lilli-Rose CARR | 09 | City of Linc Pentaqua SC | 1:04.81 | |
| 5 | 47 | Elena ALDENHOFF-KELLY | 08 | Grantham SC | 1:04.81 | |
| 6 | 45 | Madeleine SMIRTHWAITE | 08 | City of Linc Pentaqua SC | 1:05.08 | |
| 7 | 43 | Evelyn JACKSON | 08 | Lincoln Vulcans SC | 1:08.38 | |
| 8 | 41 | Eloise WALKER | 07 | Deepings SC | 1:06.54 | |
| Heat Number - 7 | ||||||
| Lane | Comp.No. | Name | YoB | Cat | Club | Time |
| 1 | 50 | Charlotte HODGIN | 08 | City of Linc Pentaqua SC | 1:03.54 | |
| 2 | 52 | Lillie HAMILTON | 08 | South Lincs Competitive SC | 1:05.68 | |
| 3 | 54 | Sophie MORSY | 07 | Boston Amateur SC | 1:06.68 | |
| 4 | 56 | Charlotte BEMROSE | 08 | Louth Dolphins SC | 1:03.42 | |
| 5 | 55 | Samantha MACIJAUSKAITE | 05 | Boston Amateur SC | 1:05.48 | |
| 6 | 53 | Katie ROSCOE | 03 | Louth Dolphins SC | 1:05.92 | |
| 7 | 51 | Hannah BRUCE | 09 | South Lincs Competitive SC | 1:05.75 | |
| 8 | 49 | Megan BROWN | 09 | Grantham SC | 1:05.35 | |
| Heat Number - 8 | ||||||
| Lane | Comp.No. | Name | YoB | Cat | Club | Time |
| 1 | 60 | Madeleine GREEN | 03 | City of Linc Pentaqua SC | 1:05.04 | |
| 2 | 66 | Mollie BRIGGS | 05 | South Lincs Competitive SC | 1:01.57 | |
| 3 | 72 | Evie TURNER | 06 | Grantham SC | 1:04.10 | |
| 4 | 78 | Bethany WALKER | 00 | Gainsborough Dolphins SC | 59.04 | |
| 5 | 75 | Jessica O'HERLIHY | 06 | South Lincs Competitive SC | 1:01.78 | |
| 6 | 69 | Evie DICKINSON | 08 | Louth Dolphins SC | 1:07.01 | |
| 7 | 63 | Grace MACDONALD | 09 | Grantham SC | 1:03.32 | |
| 8 | 57 | Corey FARLEY | 09 | Grantham SC | 1:09.29 | |
| Heat Number - 9 | ||||||
| Lane | Comp.No. | Name | YoB | Cat | Club | Time |
| 1 | 61 | Ruby WARING | 06 | Louth Dolphins SC | 1:05.94 | |
| 2 | 67 | Chloe HOPKINSON | 05 | Grantham SC | 1:05.62 | |
| 3 | 73 | Grace TURNER | 07 | Grantham SC | 1:01.39 | |
| 4 | 79 | Alexandra BULAT | 06 | Lincoln Vulcans SC | 59.13 | |
| 5 | 76 | Katie FOUNDS | 06 | City of Linc Pentaqua SC | 1:02.44 | |
| 6 | 70 | Beatrice FINCH | 06 | South Lincs Competitive SC | 1:01.79 | |
| 7 | 64 | Erin INGHAM | 08 | Louth Dolphins SC | 1:02.35 | |
| 8 | 58 | Evie LILLEY | 09 | Lincoln Vulcans SC | 1:05.74 | |
| Heat Number - 10 | ||||||
| Lane | Comp.No. | Name | YoB | Cat | Club | Time |
| 1 | 62 | Francesca HALLAM-STOTT | 07 | Grantham SC | 1:04.40 | |
| 2 | 68 | Casey CLEAVER | 06 | City of Linc Pentaqua SC | 1:03.36 | |
| 3 | 74 | Katie MALONEY | 97 | Lincoln Vulcans SC | 1:01.05 | |
| 4 | 80 | Emma CROKER | 05 | South Lincs Competitive SC | 57.42 | |
| 5 | 77 | Charlotte WRIGHT | 05 | Louth Dolphins SC | 59.92 | |
| 6 | 71 | Mia COPPING | 07 | Lincoln Vulcans SC | 1:01.27 | |
| 7 | 65 | Olivia ANSTEY | 08 | Louth Dolphins SC | 1:02.13 | |
| 8 | 59 | Wynifred OWEN | 08 | City of Linc Pentaqua SC | 1:04.34 | |