TfL's figures
TfL's freedom of information answer of November 2025 gives the average time to qualify for the candidates who qualified in each year:
| Year | Qualified | Average months |
|---|---|---|
| 2015 | 775 | 49 |
| 2016 | 870 | 48 |
| 2017 | 806 | 50 |
| 2018 | 502 | 55 |
| 2019 | 392 | 59 |
| 2020 | 180 | 63 |
| 2021 | 188 | 61 |
| 2022 | 198 | 60 |
| 2023 | 114 | 58 |
| 2024 | 110 | 53 |
The 2025 figure, 38 months for the 91 who qualified by September, covers only part of the year. The averages count only those who finished; TfL holds no figures for candidates who gave up.
What makes the difference
Hours. The candidates TfL says have passed in two years were working at it full time. Each stage also has a time limit, which keeps the pace up: see time limits for each stage.
Sources
- TfL, Learn the Knowledge of London, Learning the Knowledge
- TfL, freedom of information answer FOI-2683-2526, 11 November 2025, answer
From the guide: The stages of the Knowledge