TfL prosecute single offences all the time. They prosecute tens of thousands of people each year. As has already been said, it is possible that with a well written letter, particularly if written by or with the help of a solicitor, a warning might be issued, but I wouldn’t say it’s likely. But there’s nothing to lose by trying (except money if you use a solicitor).
If you do use a solicitor I would suggest the one that’s already replied to the thread saying they think you have a good chance.
If you don’t, I would suggest reading TfL’s prosecutions policy very carefully, drafting a letter based on that, and then posting it here for us to give feedback on.
Here’s a draft of my letter:
Dear Sir or Madam,
Re: Incident on 09/04/26
I am writing in response to your correspondence regarding an incident on 09/04/26 involving the use of my younger brother’s 11-15 Zip Oyster card on a London bus as a 19-year-old.
I would like to sincerely apologise for my actions. On that day, I used my younger brother’s Zip card despite knowing that I was not entitled to do so. I fully accept that this was wrong and a misuse of a concessionary travel card.
When I was initially questioned, I panicked and gave incorrect information about my name and age. I regret this deeply. I accept that this was dishonest and only made the situation worse. I corrected myself and provided my true details shortly after. I take full responsibility for my behaviour.
I want to emphasise that this was a lapse in judgement and not something I have done before. I now fully understand the seriousness of fare evasion and the misuse of concessionary travel cards, and I assure you that I have learnt my lesson and that this will not happen again.
I respectfully ask that you consider allowing me to resolve this matter without court proceedings. I would be grateful and more than willing to pay any outstanding fare, penalty, or administrative costs incurred because of my actions.
I am currently a first-year university student studying outside of London, and I am concerned about the potential impact a prosecution may have on my future, especially next year where a record could have a significant impact on my ability to get a summer internship. I hope you will take this into consideration.
Once again, I sincerely apologise for any inconvenience caused and for my poor conduct.
Yours faithfully,