The eligibility requirements for NBPhO are the same as for EuPhO. The contestants should not have commenced their university studies, and their age in years (truncated to an integer) should not exceed 20 on June 30th of the year of the competition. If an educational institution cannot be clearly classified as a high school, a student is considered to be eligible if less than half of his/her lectures (in average for the last two years) have been on topics related either to physics or mathematics.
Estonia, Finland, Latvia, and Sweden can each send a team of up to around 20 students (contestants), and a team leader. Each forementioned delegation is expected to include also two or more observers who are incorporated into the Academic Committee. The possibility of accepting guest teams from other countries (with up to five contestants) is discussed individually in each case.
Organizers provide accommodation for all the delegations during two nights; meals, and if needed, local transportation during the competition; tools and rooms for the examinations, moderations, and board meetings; experimental problem sets. The expenses are partially covered by the participation fees. For official teams (i.e. teams from Estonia, Finland, Latvia, and Sweden), the fee is 90€ per person, and for guest teams — 120€ per person.