Although it depends on the legislation of each country, the truth is that the usual thing is that if you do not pay a traffic fine within the legally established period, without you having presented allegations or appeals, the authorities will demand it from you by way of enforcement, with a significant surcharge that will increase as we receive notifications.

Steps to follow:
First, it is important that you know that if you are caught red-handed and sanctioned at the time, the fact that you pay the fine instantly, or within a period that is usually around 20 business days, entitles you to a bonus and You will only have to pay half of the amount with which you have been sanctioned.
Obviously, it can also happen that you do not agree with the fine that has been imposed on you, even that you are convinced that you have not committed the infraction attributed to you and, in this case, your period of allegations opens, usually 15 days, in which you can allege as much as you deem appropriate to defend yourself and present as much evidence as you deem appropriate.
Once the instructor practices the appropriate tests and carries out all the necessary steps on your allegations, he will rule on whether to admit them and the sanction is nullified or, on the contrary, to rule against you. Even so, you could still file an appeal with the corresponding Administration.
However, in the event that you decide to ignore, not pay the fine, not argue and not appeal, the Administration will claim the debt from you by executive means through an enforcement order. Here you are no longer entitled to a discount and, on the contrary, a 10% surcharge will be applied. If you still decide not to pay, the surcharge will rise to 20% and if this does not make you give up your attitude, they may initiate an embargo on your assets, from current accounts, payroll, return of Rent, the car and even real estate.
Now, appealing traffic fines is usually a way that prevents many drivers from paying the amount that is required. Any formal defect during the procedure, attributable to the Administration, prescription or failure to reliably communicate the notifications to the alleged offender, can make the fine finally vanish.