I paid an out of court settlement in 28 days instead of the 21 that it said on the letter. I have paid all of it but this does mean it is being paid late. I sent an email explaining why it was paid late. What I wanted to know is if this is something I should be worried about, because I am. Am I going to end up in court? As I said everything is paid, albeit not within the 21 days I was given.
I don't think there's a definite answer to this in that there are too many variables. Practice may vary between train companies, and I can also imagine it depending on whether the railway had already progressed the matter to court: in turn that could rely on whether they check for payment every day, or every week or every month.
On the basis of what we see here, you will probably be OK. But make sure you keep details of when you made the payment so that if the railway<edit>
doesn't does </edit> get back to you, you can easily show them details of your payment. If it does turn out that they want to prosecute, then get back to us and we will try to help.
(edited to correct a typo/muddled thinking)