A 4-phase feeding program was applied: phase 1 (day 1 – 10), phase 2 (day 11 – 21), phase 3 (day 22 – 30) and phase 4 (day 31 – 38). In phase 1, an aP content of 5.4 g/kg of feed was required for realizing maximal performance. Phase 2 required 4.3 g aP per kg of feed, and phase 4 2.6 g aP per kg of feed. In phase 3, performance of the broilers was not affected by dietary aP content, but for realizing maximal tibia ash content in this phase, 3.8 g aP per kg was required. It is concluded that the required dietary aP levels for maximal performance in phases 1 and 2 are about 30% higher than the current CVB (2012) recommendations. For these phases, aP recommendations should be reconsidered. Current recommendations for phase 3 and 4 meet the requirements for maximal performance.