As soon as you start planning your event, you should find out which licences and permits you need. The permits needed depend on the event in question; but at least a permission to use the location and a notice of public event to the police are mandatory for almost all events.
As the organiser, you are responsible for all the permits. That includes making sure that all permits held by sub-contractors and vendors, are adequate and up to date. Organising an event without the relevant permits is not allowed, and the authorities can discontinue any unauthorised events. When your licences and permits are in order, you are better protected in case anything happens.
Some of the licences and permits of Finnish authorities are not available in English. If that is the case, you can contact the relevant authority or Tampere Event Services. In many cases, you can give them the relevant information via email or in person.
The most common permits and licences for a public event:
Other permits and licences for a public event: