Reducing phosphorus (P) excretion in laying hen production is a challenge. In the digestive tract, calcium (Ca) can form de novo unavailable complexes with phytate, impairing phytase efficiency to release non-phytic P (NPP) from phytate. In broilers, it has been shown that coarse limestone particles (CL) limit the formation of Ca−phytate complexes. Thus, the effect of CL and microbial phytase was investigated in laying hens between 31 and 35 wk of age to study the potential beneficial effect of CL incorporation on P utilization. Seventy-two Lohmann Tradition laying hens were randomly assigned to one of the four experimental diets. A 2×2 factorial arrangement was used with two levels of phytase and basal available P (aP); 0 FTU/kg with 0.30% aP or 300 FTU/kg with 0.15% aP and two limestone particle sizes (LmPS); fine particles (FL, <0.5 mm) or a mix (MIX) of 75% CL (2-4 mm) and 25% FL. Diets contained equivalent levels of Ca (3.5%), phytic P (PP, 0.18%) and, considering the phytase P equivalency, equivalent levels of aP (0.30%). Egg production and average daily feed intake (ADFI) were measured weekly throughout the experimentation. Tibia ash (%), apparent pre-caecal digestibility (APCD) of P and Ca (%) and PP disappearance at the ileal level (%) were measured. No differences were observed between treatments in ADFI, FCR and tibia ash. Phytase and CL together increased the APCD of Ca by 7.3 percentage points (Phytase × LmPS, P<0.001). Hens fed with FL and phytase exhibited a lower APCD of P compared with hens fed FL without phytase, while no differences were observed in hens fed with CL (Phytase × LmPS, P<0.001). Additionally, hens fed with FL and phytase showed a lower PP disappearance at the ileal level than hens fed with CL and phytase (Phytase × LmPS, P=0.005). These results may be explained by a lower formation of Ca-phytate complexes when limestone was provided as CL, and thus a higher availability of minerals for the animal. This strategy may therefore help improving the utilization of P and Ca and reducing P excretion in laying hens.