A1 exhibitions can be approved six to 12 years before the opening date. According to the regulations specified in the BIE Convention, a gap of two years between A1 Expos should be respected. Only one A1 Expo can be held in one year. World Horticultural Expos of A1 category should not be held in the same years as other World Expos approved by the BIE, i.e. in the years ending in the numbers 0 or 5. An A1 Expo can only be held in the same country if a period of ten years between two Expos is observed. The table below reveals the current A1 Expos. It also shows the available Expo Years and the bidding deadline, the flowers represent closed bidding.
B exhibitions can be approved between 3-10 years before the opening date. AIPH may approve up to three B category Expos per year. There should be an interval of at least three months between respective opening dates when they take place on the same continent and at least three weeks on different continents. Their opening dates must not clash. The table below reveals the current B Expos. It also shows the available Expo Years and the bidding deadline, the flowers represent closed bidding.