The answer is No.
You can start by entering a rally by applying for a day licence on your entry form. A day licence or an event licence is usually £10. You add this to your entry fee.
When you sign on for the rally the organisers will request you complete and sign an additional form (in duplicate) – this is your day / event licence.
It may be worth considering an ACU Licence if you intend to do more than 4 events in the year, an ACU Enduro licence is £40 for the year.
Our advice would be to try a couple of events on a day licence and if you plan more events get a full ACU licence.